#include <bits/stdc++.h>
using namespace std;
int main(){
  long long V, T, P;
  cin >> V >> T >> P;
  V *= P + 1;
  if (V % (T - 1) == 0){
    cout << V / (T - 1) * T << endl;
  } else {
    cout << V / (T - 1) * T + V % (T - 1) + 1 << endl;
  }
}