#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

#define FOR(i, a, b) for (ll i = a; i <= (ll)(b); i++)

int main()
{
  cin.tie(0);
  ios_base::sync_with_stdio(false);

  ll v, t, p;
  cin >> v >> t >> p;

  ll ans = 0,vmax;
  vmax = (p + 1) * v;

  ans=vmax+(vmax-1)/(t-1)+1;
  cout << ans << endl;

  return 0;
}