#include"bits/stdc++.h" using namespace std; int main(){ long long a,b,c,d,e,f,g,h,s,z; char i,j,k,l; cin>>a>>i>>b>>j>>c>>d>>k>>e>>l>>f; a*=3600; d*=3600; b*=60; e*=60; s=a+b+c; z=d+e+f; cin>>g; h=z-s; cout<<h*g;}