#define F(i,n)for(i=0;i<n;i++)
m;d[200][202][100];a;e;z;k;l;i;j;x;y;
int main(n){
	scanf("%d%d",&n,&m);a=z=2*n;
	F(k,m)F(i,n)F(j,n)scanf("%d",&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;}
	a=!printf("%d",a-1);
}