#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,h,m,s;
	char a,d;
	cin>>h>>a>>m>>d>>s;
	n+=h*3600+m*60+s;
	cin>>h>>a>>m>>d>>s;
	s+=h*3600+m*60;
	cout<<n-s;
	return 0;
}

/**************************************************************
	Problem: 1101
	User: zzz
	Language: C++
	Result: Accepted
	Time:16 ms
	Memory:2072 kb
****************************************************************/