直接抄吧~

#include <iostream>
using namespace std;
int main()
{
	//还是得用long long才能ac
	long long a,b,c,d;
	cin >> a >> b >> c >> d;
	cout << (a-b) * (c+d);
	
	return 0;
}

int不行，longlong才AC

#include <stdio.h>
long long a, b, c, d;
int main()
{
    scanf("%lld %lld %lld %lld\n", &a, &b, &c, &d);
    printf("%lld\n", (a - b) * (c + d));
    return 0;
}

确实要用long long