#include <bits/stdc++.h>
using namespace std;
int main(){
    int i,o,p,ii,oo,pp;
    char ooo;
    cin>>ii>>ooo>>oo>>ooo>>pp>>i>>ooo>>o>>ooo>>p;
    cout<<ii*3600+oo*60+pp-i*3600-o*60-p;
    return 0;
}
/**************************************************************
	Problem: 1101
	User: wngjinming
	Language: C++
	Result: Accepted
	Time:18 ms
	Memory:2072 kb
****************************************************************/