#include<bits/stdc++.h>
/*
#pragma optimize ("g",on)
#pragma GCC optimize("inline")
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize ("03")
#pragma GCC target ("sse,sse2,sse3,ssse3,sse4,popcnt,abm,avx2,mmx,fma,avx,tune=native")
*/
//01001101 01100001 01101011 01101000 01100001 01100111 01100001 01111001
using namespace std;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define ll long long
#define pb push_back
#define sz(a) a.size()
#define nl '\n'
#define popb pop_back()
#define ld double
#define ull unsigned long long
#define ff first
#define ss second
#define fix fixed << setprecision
#define pii pair<int, int>
#define E exit (0)
#define int long long
const int inf = 1e9, N = 2e5 + 1, mod = 998244353;
vector<pii> dir = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
int n, k;
int cnt0[N], cnt1[N];
void f(int x, int y, int val) {
x = (x + val - 1) / val;
y = (y + val - 1) / val;
if (x % 2 == y % 2) cnt0[val]++;
else cnt1[val]++;
}
bool prime(int n) {
for (int i = 2; i <= sqrt(n); i++) if (n % i == 0) return 0;
return 1;
}
main() {
//freopen("cowrect.in", "r", stdin);
//freopen("cowrect.out", "w", stdout);
ios_base::sync_with_stdio(NULL);
cin.tie(NULL);
cin >> n >> k;
if (prime(n)) {
int cnt0 = 0, cnt1 = 0;
for (int i = 1; i <= k; i++) {
int x1, y1, x2, y2;
cin >> x1 >> y1 >> x2 >> y2;
if (x1 % 2 == y1 % 2) {
cnt0++;
}else {
cnt1++;
}
}
cout << min(cnt0 + n * n / 2 - cnt1, cnt1 + n * n / 2 + 1 - cnt0);
return 0;
}
for (int i = 1; i <= k; i++) {
int x1, y1, x2, y2;
cin >> x1 >> y1 >> x2 >> y2;
for (int val = 1; val <= sqrt(n); val++) {
if (n % val == 0) {
f(x1, y1, val);
if (n / val != val)
f(x1, y1, n / val);
}
}
}
int mn = inf;
for (int i = 1; i < n; i++) {
if (n % i) continue;
mn = min(mn, min(cnt0[i] + (n / i * (n / i)) / 2 * i * i - cnt1[i], cnt1[i] + (n / i * (n / i) + 1) / 2 * i * i - cnt0[i]));
}
cout << mn;
}
