#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

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

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

  return 0;
}