这玩意数值非常大，极其缺德，错误示范：

#include<cstdio>
int main()
{
	long long x1,x2,y1,y2;
	scanf("%ld %ld",&x1,&x2);
	scanf("%ld &ld",&y1,&y2);
	long long maxNum=x2*y2,minNum=x1*y1;
	if(maxNum<=2147483647&&minNum>=(-2147483647))
	{
		printf("int");
	}
	else 
	{
		printf("long long int");
	}
}