//#pragma GCC optomize ("Ofast")
//#pragma GCC optomize ("unroll-loops")
//#pragma GCC target ("avx,avx2,fma")
#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define sz size
#define cl clear
#define ins insert
#define ers erase
#define pii pair < int , int >
#define pll pair< long long , long long >
#define all(x) x.begin() , x.end()
#define ios ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define file(s) if (fopen(s".in", "r")) freopen(s".in", "r", stdin), freopen(s".out", "w", stdout)
#define tostr(x) to_string(x)
#define tonum(s) atoi(s.c_str())
#define seon(x) setprecision(x)
#define bpop(x) __builtin_popcount(x)
#define deb(x) cerr << #x << " = " << x << endl;
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ldb;
const double PI = 3.14159265;
const ll N = 1e5+5;
const ll mod = 1e9+7;
const ll inf = 1e9;
const ll INF = 1e18;
using namespace std;
struct {
int x1,y1,x2,y2;
}t[N];
pair<int,int> get(int l, int r , int len) {
l --;
r --;
int sz = r-l+1;
int ev = 0;
int nxl = l/len*len+len;
if(l/len%2 == 0) ev += min(r+1, nxl) - l;
l = nxl;
if(l > r) return {ev, sz-ev};
int pdr = r/len*len-1;
if(r/len%2 == 0) {
ev += r-max(pdr,l-1);
}
r = pdr;
if(l > r) return {ev, sz-ev};
if(l/len%2 != r/len%2) {
ev += (r-l+1)/2;
}
else {
ev += ((r-l+1)/len+(l/len%2==0))/2*len;
}
return {ev, sz-ev};
}
void solve(){
// int l, r,k1;
// cin>>l>>r>>k1;
// cout << get(l,r,k1).F << ' ' << get(l,r,k1).S;
// return;
int n , k;
cin>> n >> k;
int bs = 0;
for(int i = 1; i <= k; i ++) {
cin >> t[i].x1 >> t[i].y1 >> t[i].x2 >> t[i].y2;
bs += (t[i].x2-t[i].x1+1)*(t[i].y2-t[i].y1+1);
}
vector<int> dels;
for(int i = 1; i*i <= n; i ++) {
if(n%i == 0) {
dels.push_back(i);
if(n/i != i && i > 1) dels.push_back(n/i);
}
}
sort(all(dels));
int ans = inf;
for(auto len: dels) {
int m = n/len;
int ob = (m*m - (m*m/2)) * len*len;
int rb = 0;
int ww = 0;
for(int i = 1; i <= k; i ++) {
pair<int,int> X = get(t[i].x1, t[i].x2, len);
pair<int,int> Y = get(t[i].y1, t[i].y2, len);
rb += X.F * Y.F;
rb += X.S * Y.S;
ww += X.F * Y.S;
ww += X.S * Y.F;
}
// cout << len << ' ' << rb << ' ' << ww << '\n';
// cout << "ob: " << ob << '\n';
// cout << "posss " << ww + (ob-rb) << ' ' << rb + (n*n-ob-ww) << '\n';
ans = min(ans, ww + (ob-rb));
ans = min(ans, rb + (n*n-ob-ww));
}
cout << ans;
}
signed main(){
ios;
int t = 1;
// cin >> t;
while(t--) solve();
return 0;
}
/*
*/
