#include<iostream>
#define F(i,n)for(int i=0;i<n;i++)
int n,m,d[200][202][100],a,e,z;
int main(){
	std::cin>>n>>m;a=z=2*n;
	F(k,m)F(i,n)F(j,n)(std::cin>>e),d[k][i][j]=d[k][n+j][i]=d[k][z-(i!=j)][i]=d[k][n-i-j-1?z-1:z+1][i]=e;
	F(k,m)F(l,k)F(i,z+2)F(j,z+2){e=z;F(x,n)F(y,n)e-=d[k][i][x]==d[l][j][y];a=e<a?e:a;}
	std::cout<<a-1;
}