int main()
{
	int r,i,j,a[505][505],m1,m2,n1,n2,sum=0;
	scanf("%d",&r);
	m1=r;
	n1=r;
	m2=0;
	n2=0;
	for(i=0;i<r;i++){
		for(j=0;j<r;j++){
			scanf("%d",&a[i][j]);
			if(a[i][j]==0){
				if(i<=m1&&j<=n1){
					m1=i;
					n1=j;
				}
				if(i>=m2&&j>=n2){
					m2=i;
					n2=j;
				}
			}
		}
	}
    sum=(m2-m1-1)*(n2-n1-1);
	printf("%d",sum);
	return 0;
}