不喜勿喷！

#include <iostream>
#include <cstdio>
using namespace std;
short h1, m1, h2, m2; 
int main()
{
	cin >> h1 >> m1 >> h2 >> m2;
	cout << (h2 - h1) * 60 + (m2 - m1);
	
	return 0;
}