#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define ff first
#define ss second
#define pii pair<int, int>
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
int n, k;
cin >> n >> k;
pii p1[k], p2[k];
for (int i = 0; i < k; i++) {
cin >> p1[i].ff >> p1[i].ss >> p2[i].ff >> p2[i].ss;
p1[i].ff--; p1[i].ss--; p2[i].ff--; p2[i].ss--;
}
ll ans = LLONG_MAX;
for (int ii = 1; ii * ii <= n; ii++) {
if (n % ii) continue;
for (auto i : {ii, n / ii}) {
if (i == n) continue;
int x = n / i;
ll cnt1 = ((ll)((x + 1) >> 1) * ((x + 1) >> 1) + (ll)(x >> 1) * (x >> 1)) * i * i;
ll cnt2 = (ll)n * n - cnt1;
for (int j = 0; j < k; j++) {
pii x = p1[j], y = p2[j];
vector<pair<pii, pii>> v;
if (x.ss / i != y.ss / i) {
if (x.ss % i) {
v.push_back({x, {y.ff, x.ss + i - x.ss % i - 1}}); x.ss += i - x.ss % i;
}
if ((y.ss + 1) % i) {
v.push_back({{x.ff, y.ss - y.ss % i}, y}); y.ss -= y.ss % i + 1;
}
}
if (x.ss <= y.ss) v.push_back({x, y});
vector<pair<pii, pii>> u;
for (auto [x, y] : v) {
if (x.ff / i != y.ff / i) {
if (x.ff % i) {
u.push_back({x, {x.ff + i - x.ff % i - 1, y.ss}}); x.ff += i - x.ff % i;
}
if ((y.ff + 1) % i) {
u.push_back({{y.ff - y.ff % i, x.ss}, y}); y.ff -= y.ff % i + 1;
}
}
if (x.ff <= y.ff) u.push_back({x, y});
}
for (auto [x, y] : u) {
bool tr = (((x.ff / i) & 1) == ((x.ss / i) & 1));
int r = max(1, (y.ff - x.ff + 1) / i), c = max(1, (y.ss - x.ss + 1) / i);
cnt1 -= (ll)((r & 1) && (c & 1) ? (tr ? 1 : -1) : 0) * min(i, y.ff - x.ff + 1) * min(i, y.ss - x.ss + 1);
cnt2 -= (ll)((r & 1) && (c & 1) ? (tr ? -1 : 1) : 0) * min(i, y.ff - x.ff + 1) * min(i, y.ss - x.ss + 1);
}
}
ans = min({ans, cnt1, cnt2});
}
}
cout << ans;
}
