n;m;b;d;z;k;
c[200][100][100];
u[2000000];
i(v){scanf("%d",&v);return v;}

#define L(v,n)for(v=0;v<n;++v)

#define G(a){++k;L(y,n)u[c[z]a]=k;f();}
#define H(a){e=0;L(y,n)e+=u[c[d]a]!=k;if(b>e)b=e;}

f(d,e,x,y){
	L(d,m)if(d-z){
		L(x,n)H([x][y])
		L(x,n)H([y][x])
		H([y][y])
		H([y][~y+n])
	}
}

main(x,y){
	b=n=i();m=i();
	L(z,m)L(y,n)L(x,n)c[z][y][x]=i();
	L(z,m){
		L(x,n)G([x][y])
		L(x,n)G([y][x])
		G([y][y])
		G([y][~y+n])
	}
		
	printf("%d",n+b-1);
	return 0;
}