#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  Int a,b,c;
  cin>>a>>b>>c;
  Int l=0,r=c;
  while(l+1<r){
    Int m=(l+r)>>1;
    __int128_t x=m/a,y=m-x;
    if(x*b+y>=c) r=m;
    else l=m;
  }
  cout<<r<<endl;
  return 0;
}