#include<algorithm>#include<iostream>#include<cstring>#include<cstdio>#include<cmath>using namespace std;#define N 105int n,m,x,y,now,ans;int cnt[N][N];int main(){ scanf("%d%d",&n,&m); for (int i=1;i<=m;++i) { scanf("%d%d",&x,&y); ++cnt[x][y]; } for (int i=1;i<=n;++i) for (int j=1;j<=n;++j) { now=cnt[i][j]; for (int k=i-1;k>=1;--k) now+=cnt[k][j]; for (int k=i+1;k<=n;++k) now+=cnt[k][j]; for (int k=j-1;k>=1;--k) now+=cnt[i][k]; for (int k=j+1;k<=n;++k) now+=cnt[i][k]; x=i-1,y=j-1; while (x>0&&y>0) now+=cnt[x][y],--x,--y; x=i+1,y=j+1; while (x<=n&&y<=n) now+=cnt[x][y],++x,++y; x=i+1,y=j-1; while (x<=n&&y>0) now+=cnt[x][y],++x,--y; x=i-1,y=j+1; while (x>0&&y<=n) now+=cnt[x][y],--x,++y; if (now==m) ++ans; }
