#include <bits/stdc++.h>
using namespace std;
typedef pair<int64_t,int64_t> ii;
int64_t n,k,odd,even,res=1e12;
vector<ii> g1[100005],g2[100005];
void ReadInt(int64_t &number)
{
number=0;
int64_t c=getchar();
while(c<'0'||c>'9')
c=getchar();
for(;('0'<=c&&c<='9');c=getchar())
number=number*10+c-48;
}
int64_t Cal(int64_t u,int64_t v,int64_t block)
{
return ((u-1)/block+1+(v-1)/block+1)%2;
}
void Update(int64_t i,int64_t l,int64_t r,int64_t block,int64_t val)
{
int64_t ll=(l-1)/block+2;
int64_t rr=(r-1)/block;
if(ll==rr+2)
{
if(Cal(i,l,block)==1)
odd+=(r-l+1)*val;
else
even+=(r-l+1)*val;
return;
}
odd+=(rr-ll+1)/2*block*val;
even+=(rr-ll+1)/2*block*val;
if((rr-ll+1)%2==1)
{
if(Cal(i,(l-1)*block+1,block)==1)
odd+=block*val;
else
even+=block*val;
}
if(Cal(i,l,block)==1)
odd+=((ll-1)*block-l+1)*val;
else
even+=((ll-1)*block-l+1)*val;
if(Cal(i,r,block)==1)
odd+=(r-(rr*block))*val;
else
even+=(r-(rr*block))*val;
}
void Check(int64_t block)
{
int64_t tmp=n/block;
int64_t sodd=0,seven=0,codd,ceven;
if(tmp%2==0)
codd=ceven=n*n/2;
else
{
ceven=(n*n+block*block)/2;
codd=n*n-ceven;
}
odd=even=0;
for(int64_t i=1;i<=n;i++)
{
for(int64_t j=0;j<g1[i].size();j++)
Update(i,g1[i][j].first,g1[i][j].second,block,1);
sodd+=odd;
seven+=even;
for(int64_t j=0;j<g2[i].size();j++)
Update(i,g2[i][j].first,g2[i][j].second,block,-1);
}
res=min(res,min(codd-sodd+seven,ceven-seven+sodd));
}
int main()
{
ios_base::sync_with_stdio(false);
//freopen("TEST.INP","r",stdin);
//freopen("TEST.OUT","w",stdout);
ReadInt(n);
ReadInt(k);
int64_t u1,v1,u2,v2;
while(k--)
{
ReadInt(u1);
ReadInt(v1);
ReadInt(u2);
ReadInt(v2);
g1[u1].push_back(ii(v1,v2));
g2[u2].push_back(ii(v1,v2));
}
for(int64_t i=1;i<n;i++)
if(n%i==0)
Check(i);
cout<<res;
}
