#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
#define pb push_back
#define all(x) x.begin() x.end()
#define MOD (1e9+7)
const int N = 1e6;
ll n, k, ans = 1e18;
vector<array<ll, 4>> vv;
ll wh(ll x, ll y, ll d){
x++, y++;
if(x <= 0 || y <= 0) return 0;
ll res = (x / d) * (y / d) / 2 * d * d;
if(x % (2*d) >= d){
ll y1 = y / (2*d) * 2*d;
res += y1 / (2*d) * (x % d) * d;
res += (x % d) * min(d, y % (2*d));
}else{
ll y1 = y / (2*d) * 2*d;
res += y1 / (2*d) * (x % d) * d;
}
if(y % (2*d) >= d){
ll x1 = x / (2*d) * 2*d;
res += x1 / (2*d) * (y % d) * d;
res += (y % d) * min(d, x % (2*d));
}else{
ll x1 = x / (2*d) * 2*d;
res += x1 / (2*d) * (y % d) * d;
}
return res;
}
ll bl(ll x, ll y, ll d){
x++, y++;
if(x <= 0 || y <= 0) return 0;
return x * y - wh(x - 1, y - 1, d);
}
void solve(){
cin >> n >> k;
int a = 0;
for(int i = 0; i < k; ++i){
int x1, x2, y1, y2; cin >> x1 >> y1 >> x2 >> y2;
vv.pb({x1-1,y1-1,x2-1,y2-1});
}
for(ll i = 1; i < n; ++i){
if(n % i == 0){
for(int rep = 0; rep < 2; ++rep){
ll c = 0;
for(auto v: vv){
ll white = wh(v[2], v[3], i) - wh(v[0] - 1, v[3], i) - wh(v[2], v[1] - 1, i) + wh(v[0] - 1, v[1] - 1, i);
ll black = bl(v[2], v[3], i) - bl(v[0] - 1, v[3], i) - bl(v[2], v[1] - 1, i) + bl(v[0] - 1, v[1] - 1, i);
ll val = white - black;
if(!rep) c += val;
else c -= val;
}
ans = min(ans, c + (rep ? (n/i)*(n/i)/2*i*i : ((n/i)*(n/i) + 1)/2*i*i));
}
}
}
cout << ans;
}
int main(){
solve();
return 0;
}
