#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

int main(void) {
  ll a, b, c;
  cin >> a >> b >> c;

  if (b == 1) {
    cout << c << endl;
  } else {
    ll ng = 0, ok = c;
    while (ok - ng > 1) {
      ll m = (ng + ok) / 2;
      if (m / a >= (c - m + b - 2) / (b - 1)) ok = m;
      else ng = m;
    }
    cout << ok << endl;
  }

  return 0;
}