# include <stdio.h>
# include <bits/stdc++.h>
#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define For(i,x,y) for (int i = x; i <= y; i ++)
#define FOr(i,x,y) for (int i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0)
#define x1 dlp
#define y1 kdkdf
// ROAD to... Red
using namespace std;
inline bool isvowel (char c) {
c = tolower(c);
if (c == 'a' || c == 'e' || c == 'i' || c == 'y' || c == 'o' || c == 'u') return 1;
return 0;
}
const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;
const int M = 22;
const int pri = 997;
const int Magic = 2101;
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
int n, k;
int x1[N], y1[N], x2[N], y2[N];
ll cell (ll x, ll y, ll m) {
x --, y --;
x /= m, y /= m;
return x + y;
}
ll solve (ll x) {
ll res = ((n / x * (ll)n / x) / 2ll) * x * x;
ll ans = n * (ll) n - res;
// cout << res << ' ' << ans << '\n';
For (i, 1, k) {
if (cell(x1[i], y1[i], x) % 2 == 1) ans ++, res --;
else res ++, ans --;
}
return min(res, ans);
}
int main () {
cin >> n >> k;
For (i, 1, k) {
cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
}
ll ans = n * (ll)n;
For (i, 1, n - 1) {
if (n % i == 0)
ans = min(ans, solve (i));
}
cout << ans;
return Accepted;
}
// Coded By OB
