#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast")
#define fi first
#define se second
#define ll long long
using namespace std;
const int N = 2e5 + 7;
const int M = 23;
const int mod = 998244353;
ll n,k;
ll A[N];
ll B[N];
ll C[N];
ll D[N];
ll fg[M][M];
ll f( ll x , ll y , ll div )
{
ll x1 = y / div;
ll y1 = x / div;
x1 = x1 * y1 + 1;
x1 /= 2;
x1 *= div * div;
ll a = y % div;
ll b = x % div;
if( ((y - 1) / div % 2 == 0 && 1 / div % 2 == 0) || y < div ){
x1 += ((x / div + 1) / 2) * div * a;
}else{
x1 += x / div / 2 * div * a;
}
if( ((x - 1) / div % 2 == 0) ){
x1 += (y / div + 1) / 2 * div * b;
}else{
x1 += y / div / 2 * div * b;
}
if( ((x - 1) / div % 2 == 1 && (y - 1) / div % 2 == 1) || ((x - 1) / div % 2 == 0 && (y - 1) / div % 2 == 0) ){
x1 += (x % div) * (y % div);
}
//cout << x << " " << y << " " << div << " " << x1 << " " << fg[x][y] << "\n";
return x1;
}
void solve1()
{
cin >> n >> k;
vector < ll > div;
for( int i = 1; i < n; i++ ){
if( n % i == 0 )div.push_back(i);
}
for( int i = 0; i < k; i++ ){
cin >> A[i] >> B[i] >> C[i] >> D[i];
}
for( ll i = 1; i <= 10; i++ ){
for( ll j = 1; j <= 10; j++ ){
fg[i][j] = fg[i - 1][j] + fg[i][j - 1] - fg[i - 1][j - 1] + (((i) % 2 == 1 && (j) % 2 == 1) ||
((i) % 2 == 0 && (j) % 2 == 0));
}
}
ll ans = 1e14;
for( int i = 0; i < (int)div.size(); i++ ){
ll nn = n / div[i];
ll B1 = (nn + 1) / 2;
ll B2 = nn / 2;
B1 *= div[i] * div[i];
B2 *= div[i] * div[i];
B1 *= (nn + 1) / 2;
B2 *= nn / 2;
B1 += B2;
ll B3 = (nn) / 2;
ll B4 = (nn + 1) / 2;
B3 *= div[i] * div[i];
B4 *= div[i] * div[i];
B3 *= (nn + 1) / 2;
B4 *= (nn) / 2;
B3 += B4;
vector < ll > w(k , 0);
vector < ll > b(k , 0);
for( int j = 0; j < k; j++ ){
ll x = f(C[j] , D[j] , div[i]) - f(C[j] , B[j] - 1 , div[i]) -
f(A[j] - 1, D[j] , div[i]) + f(A[j] - 1 , B[j] - 1 , div[i]);
ll y = (C[j] - A[j] + 1) * (D[j] - B[j] + 1);
w[j] = y - x;
b[j] = x;
}
ll x = 0;
ll y = 0;
//cout << B1 << " " << B3 << "\n";
for( int j = 0; j < k; j++ ){
B1 -= b[j];
x += w[j];
y += b[j];
B3 -= w[j];
//if( div[i] == 1 )cout << b[j] << " ";
}
//cout << "\n";
//cout << B1 + x << " " << B3 + y << " " << div[i] << "\n";
ans = min(ans , B1 + x);
ans = min(ans , B3 + y);
}
cout << ans;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
//freopen( "input.txt" , "r" , stdin );
//freopen( "output.txt" , "w" , stdout );
int cghf = 1;//cin >> cghf;
while( cghf-- ){
solve1();
}
}
