#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ff first
#define ss second
#define pb push_back
const int N=3e3;
int a[N][N];
void subtsk1(int n){
int ans=n*n/2;
for(int i=1;i<n;i++){
if(n%i==0){
int b=n*n/i/i;
ans=min(ans,b/2*i*i);
}
}
cout<<ans;
}
bool check(int n){
for(int i=2;i<=sqrt(n);i++){
if(n%i==0)return 0;
}
return 1;
}
void subtsk2(int n, int m){
int a=0;
int b=0;
int d=n*n-n*n/2;
int e=n*n/2;
for(int i=0;i<m;i++){
int x,y;
cin>>x>>y>>x>>y;
if(x%2==y%2){
a++;
}
else{
b++;
}
}
cout<<min(d-a+b,e-b+a);
}
void sbtsk3(int n, int m){
int ans=n*n;
vector<pair<int,int>>vc;
for(int i=0;i<m;i++){
int x,y;
cin>>x>>y>>x>>y;
vc.pb({x,y});
}
for(int i=1;i<=n/2;i++){
if(n%i==0){
int a=0;
int b=0;
for(auto p:vc){
int x=p.ff;
int y=p.ss;
int t=i*2;
if((1<=x%t and x%t<=i and 1<=y%t and y%t<=i) or ( !(1<=x%t and x%t<=i) and !(1<=y%t and y%t<=i))){
a++;
}
else{
b++;
}
}
int bc=n*n/i/i;
int e=bc/2 * i* i;
int d=(bc-bc/2)*i*i;
//cout<<" :: " <<a<<" "<<b<<" "<<d<<" "<<e<<endl;
ans=min(ans,min(d-a+b,e-b+a));
}
}
cout<<ans;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n,m;
cin>>n>>m;
if(m==0){
subtsk1(n);
return 0;
}
if(check(n)){
subtsk2(n,m);
return 0;
}
sbtsk3(n,m);
}
