diff --git a/graph/connected_components_of_complement_graph/checker.cpp b/graph/connected_components_of_complement_graph/checker.cpp
new file mode 100644
index 000000000..7c6ece45a
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/checker.cpp
@@ -0,0 +1,41 @@
+#include "testlib.h"
+#include <algorithm>
+#include <vector>
+
+using namespace std;
+
+vector<vector<int>> read_ans(int n, InStream &stream) {
+    int k = stream.readInt(1, n);
+    vector<vector<int>> cc(k);
+    vector<int> pos(n, -1);
+    for (int i = 0; i < k; i++) {
+        int l = stream.readInt(1, n);
+        cc[i] = vector<int>(l);
+        for (int j = 0; j < l; j++) {
+            cc[i][j] = stream.readInt(0, n - 1);
+            if (pos[cc[i][j]] != -1) {
+                stream.quitf(_wa, "twice used vertex %d", cc[i][j]);
+            }
+            pos[cc[i][j]] = i;
+        }
+        sort(cc[i].begin(), cc[i].end());
+    }
+    sort(cc.begin(), cc.end());
+    return cc;
+}
+
+int main(int argc, char *argv[]) {
+    registerTestlibCmd(argc, argv);
+    int n = inf.readInt();
+    auto cc_ans = read_ans(n, ans);
+    auto cc_ouf = read_ans(n, ouf);
+    int k_ans = int(cc_ans.size());
+    int k_ouf = int(cc_ouf.size());
+    if (k_ans != k_ouf) {
+        quitf(_wa, "# of connected components is wrong - expected: '%d', found: '%d'", k_ans, k_ouf);
+    }
+    if (cc_ans != cc_ouf) {
+        quitf(_wa, "connected components are different");
+    }
+    quitf(_ok, "OK");
+}
diff --git a/graph/connected_components_of_complement_graph/gen/complement_of_many_paths.cpp b/graph/connected_components_of_complement_graph/gen/complement_of_many_paths.cpp
new file mode 100644
index 000000000..463ac135c
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/complement_of_many_paths.cpp
@@ -0,0 +1,53 @@
+#include <cstdio>
+#include "random.h"
+#include "../params.h"
+
+using namespace std;
+
+int get_max_n() {
+    int ok = N_MIN, ng = N_MAX + 1;
+    while (ng - ok > 1) {
+        int mid = (ok + ng) / 2;
+        if ((long long)mid * (mid - 1) / 2 <= M_MAX) {
+            ok = mid;
+        } else {
+            ng = mid;
+        }
+    }
+    return ok;
+}
+
+int main(int, char **argv) {
+    long long seed = atoll(argv[1]);
+    Random gen(seed);
+    int n = get_max_n();
+    vector<int> p(n);
+    for (int i = 0; i < n; ++i) {
+        p[i] = i;
+    }
+    gen.shuffle(p.begin(), p.end());
+    vector<vector<int>> edge(n, vector<int>(n, 1));
+    for (int i = 0; i < n - 1; ++i) {
+        if (gen.uniform_bool()) {
+            edge[p[i]][p[i + 1]] = edge[p[i + 1]][p[i]] = 0;
+        }
+    }
+    vector<pair<int, int>> output;
+    for (int i = 0; i < n; ++i) {
+        for (int j = i + 1; j < n; ++j) {
+            if (edge[i][j]) {
+                if (gen.uniform_bool()) {
+                    output.emplace_back(i, j);
+                } else {
+                    output.emplace_back(j, i);
+                }
+            }
+        }
+    }
+    gen.shuffle(output.begin(), output.end());
+    int m = int(output.size());
+    printf("%d %d\n", n, m);
+    for (pair<int, int> e : output) {
+        printf("%d %d\n", e.first, e.second);
+    }
+}
diff --git a/graph/connected_components_of_complement_graph/gen/complement_of_sparse.cpp b/graph/connected_components_of_complement_graph/gen/complement_of_sparse.cpp
new file mode 100644
index 000000000..2f8342118
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/complement_of_sparse.cpp
@@ -0,0 +1,51 @@
+#include <cstdio>
+#include "random.h"
+#include "../params.h"
+
+using namespace std;
+
+int get_max_n() {
+    int ok = N_MIN, ng = N_MAX + 1;
+    while (ng - ok > 1) {
+        int mid = (ok + ng) / 2;
+        if ((long long)mid * (mid - 1) / 2 <= M_MAX) {
+            ok = mid;
+        } else {
+            ng = mid;
+        }
+    }
+    return ok;
+}
+
+int main(int, char **argv) {
+    long long seed = atoll(argv[1]);
+    Random gen(seed);
+    int n = get_max_n();
+    int elim = n / 2;
+    vector<vector<int>> edge(n, vector<int>(n, 1));
+    for (int i = 0; i < elim; ++i) {
+        pair<int, int> p = gen.uniform_pair(0, n - 1);
+        while (!edge[p.first][p.second]) {
+            p = gen.uniform_pair(0, n - 1);
+        }
+        edge[p.first][p.second] = 0;
+    }
+    vector<pair<int, int>> output;
+    for (int i = 0; i < n; ++i) {
+        for (int j = i + 1; j < n; ++j) {
+            if (edge[i][j]) {
+                if (gen.uniform_bool()) {
+                    output.emplace_back(i, j);
+                } else {
+                    output.emplace_back(j, i);
+                }
+            }
+        }
+    }
+    gen.shuffle(output.begin(), output.end());
+    int m = int(output.size());
+    printf("%d %d\n", n, m);
+    for (pair<int, int> e : output) {
+        printf("%d %d\n", e.first, e.second);
+    }
+}
diff --git a/graph/connected_components_of_complement_graph/gen/complete.cpp b/graph/connected_components_of_complement_graph/gen/complete.cpp
new file mode 100644
index 000000000..eb75983b9
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/complete.cpp
@@ -0,0 +1,40 @@
+#include <cstdio>
+#include "random.h"
+#include "../params.h"
+
+using namespace std;
+
+int get_max_n() {
+    int ok = N_MIN, ng = N_MAX + 1;
+    while (ng - ok > 1) {
+        int mid = (ok + ng) / 2;
+        if ((long long)mid * (mid - 1) / 2 <= M_MAX) {
+            ok = mid;
+        } else {
+            ng = mid;
+        }
+    }
+    return ok;
+}
+
+int main(int, char **argv) {
+    long long seed = atoll(argv[1]);
+    Random gen(seed);
+    int n = get_max_n();
+    int m = n * (n - 1) / 2;
+    vector<pair<int, int>> edges;
+    for (int i = 0; i < n; ++i) {
+        for (int j = i + 1; j < n; ++j) {
+            if (gen.uniform_bool()) {
+                edges.emplace_back(i, j);
+            } else {
+                edges.emplace_back(j, i);
+            }
+        }
+    }
+    gen.shuffle(edges.begin(), edges.end());
+    printf("%d %d\n", n, m);
+    for (pair<int, int> e : edges) {
+        printf("%d %d\n", e.first, e.second);
+    }
+}
diff --git a/graph/connected_components_of_complement_graph/gen/example_00.in b/graph/connected_components_of_complement_graph/gen/example_00.in
new file mode 100644
index 000000000..00ed2c51c
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/example_00.in
@@ -0,0 +1,4 @@
+4 3
+1 0
+2 1
+1 3
diff --git a/graph/connected_components_of_complement_graph/gen/example_01.in b/graph/connected_components_of_complement_graph/gen/example_01.in
new file mode 100644
index 000000000..a802cdf46
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/example_01.in
@@ -0,0 +1,12 @@
+6 11
+0 1
+0 2
+0 4
+1 2
+1 3
+1 5
+2 3
+2 4
+2 5
+3 4
+4 5
diff --git a/graph/connected_components_of_complement_graph/gen/example_02.in b/graph/connected_components_of_complement_graph/gen/example_02.in
new file mode 100644
index 000000000..3f1dcc525
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/example_02.in
@@ -0,0 +1,11 @@
+5 10
+0 1
+0 2
+0 3
+0 4
+1 2
+1 3
+1 4
+2 3
+2 4
+3 4
diff --git a/graph/connected_components_of_complement_graph/gen/max_random.cpp b/graph/connected_components_of_complement_graph/gen/max_random.cpp
new file mode 100644
index 000000000..d260ee624
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/max_random.cpp
@@ -0,0 +1,26 @@
+#include "../params.h"
+#include "random.h"
+#include <cstdio>
+
+using namespace std;
+
+int main(int, char **argv) {
+    long long seed = atoll(argv[1]);
+    Random gen(seed);
+    int n = N_MAX;
+    int m = M_MAX;
+    printf("%d %d\n", n, m);
+    set<pair<int, int>> edges;
+    for (int i = 0; i < m; i++) {
+        pair<int, int> p = gen.uniform_pair(0, n - 1);
+        while (edges.count(p)) {
+            p = gen.uniform_pair(0, n - 1);
+        }
+        edges.insert(p);
+        if (gen.uniform_bool()) {
+            swap(p.first, p.second);
+        }
+        printf("%d %d\n", p.first, p.second);
+    }
+    return 0;
+}
diff --git a/graph/connected_components_of_complement_graph/gen/minimum_00.in b/graph/connected_components_of_complement_graph/gen/minimum_00.in
new file mode 100644
index 000000000..80c0cc79a
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/minimum_00.in
@@ -0,0 +1 @@
+1 0
diff --git a/graph/connected_components_of_complement_graph/gen/minimum_01.in b/graph/connected_components_of_complement_graph/gen/minimum_01.in
new file mode 100644
index 000000000..a74b3c230
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/minimum_01.in
@@ -0,0 +1 @@
+2 0
diff --git a/graph/connected_components_of_complement_graph/gen/minimum_02.in b/graph/connected_components_of_complement_graph/gen/minimum_02.in
new file mode 100644
index 000000000..5d0dfc619
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/minimum_02.in
@@ -0,0 +1,2 @@
+2 1
+0 1
diff --git a/graph/connected_components_of_complement_graph/gen/no_edge.cpp b/graph/connected_components_of_complement_graph/gen/no_edge.cpp
new file mode 100644
index 000000000..3015f1497
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/no_edge.cpp
@@ -0,0 +1,10 @@
+#include <cstdio>
+#include "random.h"
+#include "../params.h"
+
+using namespace std;
+
+int main() {
+    int n = N_MAX;
+    printf("%d 0\n", n);
+}
diff --git a/graph/connected_components_of_complement_graph/gen/star.cpp b/graph/connected_components_of_complement_graph/gen/star.cpp
new file mode 100644
index 000000000..11a68d7ba
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/gen/star.cpp
@@ -0,0 +1,20 @@
+#include <cstdio>
+#include "random.h"
+#include "../params.h"
+
+using namespace std;
+
+int main(int, char **argv) {
+    long long seed = atoll(argv[1]);
+    Random gen(seed);
+    int n = N_MAX;
+    int m = n - 1;
+    printf("%d %d\n", n, m);
+    int center = gen.uniform(0, n - 1);
+    for (int i = 0; i < n; ++i) {
+        if (i != center) {
+            printf("%d %d\n", i, center);
+        }
+    }
+    return 0;
+}
diff --git a/graph/connected_components_of_complement_graph/hash.json b/graph/connected_components_of_complement_graph/hash.json
new file mode 100644
index 000000000..41592afbe
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/hash.json
@@ -0,0 +1,50 @@
+{
+  "complement_of_many_paths_00.in": "d65e1ab32040a0bea5fba707c4efb2a5a7e807782321deeb406a7f4f1b465f5b",
+  "complement_of_many_paths_00.out": "cdc1527d07a6ca3e01911435701ce96a69eacc3832165226322803cff94ceed4",
+  "complement_of_many_paths_01.in": "730169db156d0b22aa636192704e3b7c9656dae9910c6b71e8014f40999e32bf",
+  "complement_of_many_paths_01.out": "4b0d54b0aeb7019a1882abede61e993488b5e5ff4b91ba8844cd3d47d030d816",
+  "complement_of_many_paths_02.in": "2f61b917fa62b0fed283a83f12c126eab7757e036123427d94e03ddd30319163",
+  "complement_of_many_paths_02.out": "2a8531faf64b9866619c73d3c62c3f112378d97835c022951037fde1e4a5b1f4",
+  "complement_of_many_paths_03.in": "bf7c86a8075a9801a4af07a117ec6641db8cc303ae7c058c4df3cf85b1ba4061",
+  "complement_of_many_paths_03.out": "d8191837dd846fc196194db27021092e827f6adf3ec8721aede3bbfd70d66350",
+  "complement_of_many_paths_04.in": "8944b42f26c76509535b042ef086baf5b3e60585464dabae3d4802d2c41f0a96",
+  "complement_of_many_paths_04.out": "13124f1bf67902e5fbf94473814d0c78c531062793b56b6ee3dd6959a1d00592",
+  "complement_of_sparse_00.in": "251902d016057f034341c640e113a3e82711cf09559536730afb283a75cf63d5",
+  "complement_of_sparse_00.out": "6d33f036779397b12e02b45c8f9704cf0351f7565c02fd7011cc248489f4b351",
+  "complement_of_sparse_01.in": "b9fa1104af50f819007fc3a80cd927a5e4e4cb03418adfd75f8d7260e5888ccd",
+  "complement_of_sparse_01.out": "87a94c39bb9731c01a7b5221b1b58b9724987813b49ccdf068291f4f3cd7dc4d",
+  "complement_of_sparse_02.in": "02ce9a1e3114889e31c0818ff2ab16b5c76d9603b418bbf91b9c2c2cfc375fd5",
+  "complement_of_sparse_02.out": "3430ad4bc27be56f226660ff22a4cfce17e206e3889895f0c42698e32413be13",
+  "complement_of_sparse_03.in": "0e55335fd3f424abed344fab7121d053823c7bb4571deb77cc99bda4831c14b8",
+  "complement_of_sparse_03.out": "85b2a9d3a187e72a47868e7259e3fd7bd2118c96dc99d247686eca741f286134",
+  "complement_of_sparse_04.in": "37a570d2fdb458bafbaaf45f747b35e9b9b69de237c566c1edfb9323576d8223",
+  "complement_of_sparse_04.out": "7937a006eccc0777079ed7f97aebd532c32b73b16325d5be41c6d264cdfeef09",
+  "complete_00.in": "8bb85cdf8012121788be0cb8de070cbc32dcb0b14313e436186d03a547465544",
+  "complete_00.out": "35356cffdcbcc676fd205a1a60951fd428282b3f0dbbda2c2229e81e15c0da01",
+  "example_00.in": "8cf683df6c2f5c13cd326ac07f51e798e5e194003f4f6e088d895148e2a9b763",
+  "example_00.out": "672ea5ac34d7c51cd5d4a75041ebe858028be1e2002f0b2ae6b21909ecdf83fe",
+  "example_01.in": "e0a2c1655d6f02bb4477782e4e836a12abeb82736aafff072fab6561276110be",
+  "example_01.out": "322c5b3204d4655974829c59f083abf32c7b52f3bd559597e145210f9cab0d66",
+  "example_02.in": "02f369096b911556d342f347851a6f997d3766501c956bed1b4e3ed810a8fc42",
+  "example_02.out": "19826a18b764e5541b7cf62880f68fdbf1b954169b3e838d72cf1071ea558170",
+  "max_random_00.in": "583ed8977219941c3bbed07acb8ca21e83de4b0aef7989866da5bf6a080285ac",
+  "max_random_00.out": "219da5b597741168f705e7eeec1102c50593f23ec03d47fbd8d38d5f54c8b811",
+  "max_random_01.in": "af9b4489be6193c78900526eea0e11af5b708e484fec3922bab6afb58e9bafc5",
+  "max_random_01.out": "219da5b597741168f705e7eeec1102c50593f23ec03d47fbd8d38d5f54c8b811",
+  "max_random_02.in": "5e2fa069562b07caf7fba6d007c9e15008385d9d1375ac19232f0d4bad3d7a92",
+  "max_random_02.out": "219da5b597741168f705e7eeec1102c50593f23ec03d47fbd8d38d5f54c8b811",
+  "max_random_03.in": "336c7920dd6138ef0ca565a8579e5d631e6785c2f87aa84ea6bfc79030eac2af",
+  "max_random_03.out": "219da5b597741168f705e7eeec1102c50593f23ec03d47fbd8d38d5f54c8b811",
+  "max_random_04.in": "6b3fc157c048daf0e1b3fedaa4ca3ebd160da73b8a6fae1c82d1bfa244da52e7",
+  "max_random_04.out": "219da5b597741168f705e7eeec1102c50593f23ec03d47fbd8d38d5f54c8b811",
+  "minimum_00.in": "f4a8ae8e74ddfb896a256de4e3099911dcaa6a9302591713898069b0bcd6e3d7",
+  "minimum_00.out": "d17b405c22d3ea8fea3ac06a001c501c1d7e5a328083f5d4a5bcce4fd97e30da",
+  "minimum_01.in": "4516f6eaaa675488778d6ca333df14bc68c27fb7d7b8015073220d4571aa9c51",
+  "minimum_01.out": "67d4a29a53c61fb2de135f2059cedf70735135da8d2a6848dc0bf5d574d5eab8",
+  "minimum_02.in": "4a6ae7226283a4b6277ce3e77a91585c0cad93929046f3c7bd9105d7ed101834",
+  "minimum_02.out": "ed9340df2899edec904960adcd2539fe18f6e765051e6bbbd5aaccc02b6f8d05",
+  "no_edge_00.in": "5fc37b8e820c7ecfdaf122cdc5a0e1e9174d5d09d0b9c7aae8aeac434ca26aed",
+  "no_edge_00.out": "219da5b597741168f705e7eeec1102c50593f23ec03d47fbd8d38d5f54c8b811",
+  "star_00.in": "81ee21ae7add6b764b36888d0c9703ab616e634c17260735cf1087f5dd14a962",
+  "star_00.out": "d77af3500c0728e06c0b134a8f2c92ad1c3cc62b97f2f2c44d3b4f1016e6a76a"
+}
\ No newline at end of file
diff --git a/graph/connected_components_of_complement_graph/info.toml b/graph/connected_components_of_complement_graph/info.toml
new file mode 100644
index 000000000..edba6c37c
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/info.toml
@@ -0,0 +1,38 @@
+title = 'Connected Components of Complement Graph'
+timelimit = 5.0
+forum = "https://github.com/yosupo06/library-checker-problems/issues/865"
+
+[[tests]]
+    name = "example.in"
+    number = 3
+[[tests]]
+    name = "max_random.cpp"
+    number = 5
+[[tests]]
+    name = "no_edge.cpp"
+    number = 1
+[[tests]]
+    name = "complete.cpp"
+    number = 1
+[[tests]]
+    name = "star.cpp"
+    number = 1
+[[tests]]
+    name = "complement_of_sparse.cpp"
+    number = 5
+[[tests]]
+    name = "complement_of_many_paths.cpp"
+    number = 5
+[[tests]]
+    name = "minimum.in"
+    number = 3
+
+[[solutions]]
+    name = "naive.cpp"
+    allow_tle = true
+
+[params]
+    N_MIN = 1
+    N_MAX = 500_000
+    M_MIN = 0
+    M_MAX = 500_000
diff --git a/graph/connected_components_of_complement_graph/sol/correct.cpp b/graph/connected_components_of_complement_graph/sol/correct.cpp
new file mode 100644
index 000000000..007d8a389
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/sol/correct.cpp
@@ -0,0 +1,63 @@
+#include <cstdio>
+#include <queue>
+#include <vector>
+using namespace std;
+
+int main() {
+    int n, m;
+    scanf("%d%d", &n, &m);
+    vector<vector<int>> g(n);
+    for (int i = 0; i < m; ++i) {
+        int a, b;
+        scanf("%d%d", &a, &b);
+        g[a].push_back(b);
+        g[b].push_back(a);
+    }
+    vector<int> cc(n, -1);
+    int cnt = 0;
+    vector<int> rem(n);
+    for (int i = 0; i < n; ++i) {
+        rem[i] = i;
+    }
+    vector<int> flg(n, 0);
+    while (!rem.empty()) {
+        int r = rem.back();
+        rem.pop_back();
+        queue<int> que;
+        cc[r] = cnt;
+        que.push(r);
+        while (!que.empty()) {
+            int v = que.front();
+            que.pop();
+            for (int u : g[v]) {
+                flg[u] = 1;
+            }
+            vector<int> nxtrem;
+            for (int u : rem) {
+                if (flg[u]) {
+                    nxtrem.push_back(u);
+                } else if (cc[u] == -1) {
+                    cc[u] = cnt;
+                    que.push(u);
+                }
+            }
+            for (int u : g[v]) {
+                flg[u] = 0;
+            }
+            rem = nxtrem;
+        }
+        ++cnt;
+    }
+    vector<vector<int>> comps(cnt);
+    for (int i = 0; i < n; ++i) {
+        comps[cc[i]].push_back(i);
+    }
+    printf("%d\n", cnt);
+    for (int i = 0; i < cnt; ++i) {
+        printf("%d", (int)comps[i].size());
+        for (int u : comps[i]) {
+            printf(" %d", u);
+        }
+        printf("\n");
+    }
+}
diff --git a/graph/connected_components_of_complement_graph/sol/naive.cpp b/graph/connected_components_of_complement_graph/sol/naive.cpp
new file mode 100644
index 000000000..991006152
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/sol/naive.cpp
@@ -0,0 +1,51 @@
+#include <cstdio>
+#include <queue>
+#include <set>
+#include <utility>
+#include <vector>
+using namespace std;
+
+int main() {
+    int n, m;
+    scanf("%d%d", &n, &m);
+    set<pair<int, int>> edges;
+    for (int i = 0; i < m; ++i) {
+        int a, b;
+        scanf("%d%d", &a, &b);
+        edges.insert(make_pair(a, b));
+        edges.insert(make_pair(b, a));
+    }
+    vector<int> cc(n, -1);
+    int cnt = 0;
+    for (int i = 0; i < n; ++i) {
+        if (cc[i] != -1) {
+            continue;
+        }
+        queue<int> que;
+        cc[i] = cnt;
+        que.push(i);
+        while (!que.empty()) {
+            int v = que.front();
+            que.pop();
+            for (int u = 0; u < n; ++u) {
+                if (!edges.count(make_pair(u, v)) && cc[u] == -1) {
+                    cc[u] = cnt;
+                    que.push(u);
+                }
+            }
+        }
+        ++cnt;
+    }
+    vector<vector<int>> comps(cnt);
+    for (int i = 0; i < n; ++i) {
+        comps[cc[i]].push_back(i);
+    }
+    printf("%d\n", cnt);
+    for (int i = 0; i < cnt; ++i) {
+        printf("%d", (int)comps[i].size());
+        for (int u : comps[i]) {
+            printf(" %d", u);
+        }
+        printf("\n");
+    }
+}
diff --git a/graph/connected_components_of_complement_graph/task.md b/graph/connected_components_of_complement_graph/task.md
new file mode 100644
index 000000000..7455063e9
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/task.md
@@ -0,0 +1,69 @@
+## @{keyword.statement}
+
+@{lang.en}
+
+You are given a simple undirected graph with $N$ vertices and $M$ edges. The $i$-th edge is $(a_i,b_i)$. Decompose the complement graph of $G$ into connected components.
+
+@{lang.ja}
+
+$N$ 頂点 $M$ 辺の単純無向グラフ $G$ が与えられる。$i$ 番目の辺は $(a_i,b_i)$ である。$G$ の補グラフを連結成分分解せよ。
+
+@{lang.end}
+
+## @{keyword.constraints}
+
+@{lang.en}
+
+- $@{param.N_MIN} \leq N \leq @{param.N_MAX}$
+- $@{param.M_MIN} \leq M \leq @{param.M_MAX}$
+- $0 \leq a_i, b_i < N$
+- The given graph is simple
+
+@{lang.ja}
+
+- $@{param.N_MIN} \leq N \leq @{param.N_MAX}$
+- $@{param.M_MIN} \leq M \leq @{param.M_MAX}$
+- $0 \leq a_i, b_i < N$
+- 与えられるグラフは単純
+
+@{lang.end}
+
+## @{keyword.input}
+
+~~~
+$N$ $M$
+$a_0$ $b_0$
+$a_1$ $b_1$
+$\vdots$
+$a_{M-1}$ $b_{M-1}$
+~~~
+
+## @{keyword.output}
+
+@{lang.en}
+
+Print the number of connected components $K$ in the first line. In the next $K$ lines, print as follows. $l$ is the number of vertices of a connected component and $v_i$ is a vertex index.
+
+@{lang.ja}
+
+$K$ を連結成分の個数として、$1+K$ 行出力する。最初の行には $K$ を出力し、その後 $K$ 行では以下のように出力する。$l$ は連結成分の頂点数であり、$v_i$ はその頂点番号である。
+
+@{lang.end}
+
+~~~
+$l$ $v_0$ $v_1$ ... $v_{l-1}$
+~~~
+
+@{lang.en}
+If there are multiple solutions, you may print any of them.
+@{lang.ja}
+正しい出力が複数存在する場合は、どれを出力しても構わない。
+@{lang.end}
+
+## @{keyword.sample}
+
+@{example.example_00}
+
+@{example.example_01}
+
+@{example.example_02}
diff --git a/graph/connected_components_of_complement_graph/verifier.cpp b/graph/connected_components_of_complement_graph/verifier.cpp
new file mode 100644
index 000000000..98832e50a
--- /dev/null
+++ b/graph/connected_components_of_complement_graph/verifier.cpp
@@ -0,0 +1,27 @@
+#include "testlib.h"
+#include "params.h"
+#include <set>
+#include <utility>
+using namespace std;
+
+int main() {
+    registerValidation();
+    int n = inf.readInt(N_MIN, N_MAX);
+    inf.readSpace();
+    int m = inf.readInt(M_MIN, M_MAX);
+    inf.readChar('\n');
+    set<pair<int, int>> edges;
+    for (int i = 0; i < m; ++i) {
+        int a = inf.readInt(0, n - 1);
+        inf.readSpace();
+        int b = inf.readInt(0, n - 1);
+        inf.readChar('\n');
+        ensure(a != b);
+        if (a > b) {
+            swap(a, b);
+        }
+        ensure(edges.count(make_pair(a, b)) == 0);
+        edges.insert(make_pair(a, b));
+    }
+    inf.readEof();
+}