
int main()
{
	int s,x,i,j,n,a1,a2,b1,b2;
	a1=0;a2=0;b1=0;b2=0;
	scanf("%d",&n);
	for (i=1;i<(n+1);i++)
	{
		for (j=1;j<(n+1);j++)
		{	
			scanf("%d",&x);
		    if ((x==0) && (a1==0)) {a1=i;a2=j;}
            if (x==0) {b1=i;b2=j;}
		}
	}
    s=(b1-a1-1)*(b2-a2-1);
	printf("%d\n",s);
	return 0;

}