#include<bits/stdc++.h>
using namespace std;
#define int long long
#define rep(n) rep1(i,n)
#define rep1(i,n) rep2(i,0,n)
#define rep2(i,a,b) for(int i=a; i<b; ++i)
#define rep3(i,a,b) for(int i=a; i>=b; --i)
#define sz(a) ((int)a.size())
#define all(a) a.begin(),a.end()
#define pow2(x) (1ll<<(x))
#ifdef i_am_noob
#define bug(...) cerr << "#" << __LINE__ << ' ' << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x){cerr << x << endl;}
template<typename T, typename ...S> void _do(T && x, S&&... y){cerr << x << ' ',_do(y...);}
#else
#define bug(...) 826
#endif
const int maxn=100005;
const int mod=1000000007;
#define y1 hhhhaura_TOI_2J
int n,k,x1[maxn],x2[maxn],y1[maxn],y2[maxn],area,ans=1e18;
inline int calc(int t, int x, int y){
if(x<0||y<0) return 0;
int a=x/t,b=y/t,res=(x/t)*(y/t)/2*t*t;
int c=a&1?(b+1)/2*t:b/2*t;
c+=y%t+1;
int d=b&1?(a+1)/2*t:a/2*t;
d+=x%t+1;
if(x==2&&y==2) bug(c,d);
if((a+b)&1) return res+c*d-(c-y%t-1)*(d-x%t-1);
return res+c*d-(c-y%t-1)*(d-x%t-1)-(x%t+1)*(y%t+1);
}
inline int calc1(int t, int id){
return calc(t,x2[id],y2[id])-calc(t,x1[id]-1,y2[id])-calc(t,x2[id],y1[id]-1)+calc(t,x1[id]-1,y1[id]-1);
}
inline int calc2(int t, int id){
return (x2[id]-x1[id]+1)*(y2[id]-y1[id]+1)-calc1(t,id);
}
signed main(){
ios_base::sync_with_stdio(0),cin.tie(0);
#ifdef i_am_noob
freopen("input1.txt","r",stdin);
freopen("output1.txt","w",stdout);
freopen("output2.txt","w",stderr);
#endif
cin >> n >> k;
rep(k) cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
rep(k) x1[i]--,y1[i]--,x2[i]--,y2[i]--;
rep(k) area+=(x2[i]-x1[i]+1)*(y2[i]-y1[i]+1);
rep(5) rep1(j,5){
int tmp=calc(2,i,j);
bug(i,j,tmp);
}
rep2(i,1,n) if(n%i==0){
int val=0;
rep1(j,k) val+=calc1(i,j);
//area-val good
//cnt(black)-(area-val)
bug(val);
val+=((n/i)&1?((n/i)*(n/i)+1)/2*i*i:(n/i)*(n/i)/2*i*i)-area+val;
ans=min(ans,val);
bug(val);
val=0;
rep1(j,k) val+=calc2(i,j);
bug(val);
val+=(n/i)*(n/i)/2*i*i-area+val;
ans=min(ans,val);
bug(val);
}
cout << ans << "\n";
}
