This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pi pair<int, int>
#define pii pair<int, pi>
#define fi first
#define se second
#ifdef _WIN32
#define getchar_unlocked _getchar_nolock
#endif
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
int A[100005], B[100005], C[100005], D[100005];
void solve(){
	int n, k;
	cin >> n >> k;
	for(int i=1;i<=k;i++)cin >> A[i] >> B[i] >> C[i] >> D[i];
	int ans = 1e18;
	for(int i=1;i<n;i++){
		if(n%i)continue;
		int tmp = ((n / i) * (n / i) / 2 * i * i), tmp2 = (((n / i) * (n / i) + 1) / 2 * i * i);
		for(int j=1;j<=k;j++){
			// count number of black rows
			int lol = (A[j] + i - 1) / i, lol2 = (B[j] + i - 1) / i;
			if(lol%2 == lol2%2)tmp2--, tmp++;
			else tmp--, tmp2++;
		}
		//cout << i << ' ' << tmp << ' ' << tmp2 << '\n';
		ans = min({ans, tmp, tmp2});
	}
	cout << ans;
}
main(){
	ios::sync_with_stdio(0);cin.tie(0);
	int tc = 1;
	//cin >> tc;
	for(int tc1=1;tc1<=tc;tc1++){
		// cout << "Case #" << tc1 << ": ";
		solve();
	}
}
Compilation message (stderr)
chessboard.cpp:34:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   34 | main(){
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