#include<bits/stdc++.h>
#define ll long long
using namespace std;

ll a,b,c;

inline bool check(ll m){
  if(m>=c)return 1;
  if(m-m/a>=c)return 1;
  if((m/a)>=c-m+m/a)return 1;
  ll sum=(m/a)*b;
  if(sum>=c-m+m/a)return 1;
  else return 0;
}

int main(){
  cin>>a>>b>>c;
  ll ng=0,ok=(ll)1e18;
  while(ok-ng>1){
    ll mid=(ok+ng)/2;
    if(check(mid)){
      ok=mid;
    }else{
      ng=mid;
    }
  }
  cout<<ok<<endl;
  return 0;
}