Cupboards.cpp

// Problem: A. Cupboards
// Contest: Codeforces - Codeforces Round #152 (Div. 2)
// URL: https://codeforces.com/problemset/problem/248/A
// Memory Limit: 256 MB
// Time Limit: 2000 ms
// Powered by CP Editor (https://github.com/cpeditor/cpeditor)

#include <bits/stdc++.h>
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define ll long long int
#define vi vector<int>
#define vii vector<int, int>
#define vc vector<char>
#define vl vector<ll>
#define mod 1000000007 
#define INF 1000000009
using namespace std;


int main()
{
     ios_base::sync_with_stdio(0);
     cin.tie(0);
     cout.tie(0);
     
     int n;
     cin >> n;
     int lc = 0, rc = 0, lo = 0, ro = 0;
     
     int a ,b;
     while(n--) {
     	cin >> a >> b;
     	if(a == 0)
     		lc++;
     	if(b == 0) 
     		rc++;
     	if(a == 1)
     		lo++;
     	if(b == 1)
     		ro++;
     }
     
     cout << min(lo,lc) + min(ro, rc) << "\n";
     
     
     
     
     
return 0;
}