那里错了？？？0分求助

    #include <bits/stdc++.h>
    using namespace std;
    int main (){
	int a, b, c, d, x, y;
	cin >> a >> b >> c >> d;
	if(b <= d){
		x = b - a;
		y = d - d;
		cout << x << y;
	}else if(b > d){
		--c;
		d = d + 60;
		x = b - a;
		y = d - d;
		cout << x << y;
	}
	return 0;
    }//请给位大佬为我这个蒟蒻 指点迷津