#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
long long s,f,m,z,zh,zhu;
char a;
int main()
{
    cin>>s>>a>>f>>a>>m>>z>>a>>zh>>a>>zhu;
    int n;
    cin>>n;
    cout<<((s-z)*3600+(f-zhu)*60+(m-zhu))*n;
    return 0;
}