#include<bits/stdc++.h> using namespace std; int x,y,t,ans; int main(){ cin>>x>>y>>t; /*ans/x<=ans/y+t ans*(1/x-1/y)<=t ans<=t/(1/x-1/y) ans<=t/[(y-x)/xy] ans<=t*xy/y-x */ ans=t*x*y/(y-x); cout<<ans; return 0; }