https://codeforces.com/problemset/problem/978/E
https://codeforces.com/problemset/problem/980/E
https://codeforces.com/problemset/problem/1009/E
// https://codeforces.com/problemset/problem/1007/E
https://codeforces.com/problemset/problem/1012/F
npm run test:watch