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

#define ll long long
#define rep(i, n) for (int i = 0; i < (n); i++)
#define P pair<int, int>

int main() {
  ll v, t, p;
  cin >> v >> t >> p;

  ll cnt = ((p+1)*v+t-1)/(t-1);

  cout << (p+1)*v + cnt << endl;


}