#include<bits/stdc++.h> using namespace std; int a[1000010],t[1000010]; long long ans=0; int main(){ //freopen("a3.in","r",stdin); //freopen("a3.out","w",stdout); double x,y,t; cin>>x>>y>>t; double cha=x*t; double six=y-x; double k=cha/six; double lo=k+t; double num=lo*x; cout<<(int)num<<endl; return 0; }