#include <bits/stdc++.h>

using namespace std;

using ll = long long;

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

  if (a > b) swap(a, b);

  auto f = [&](ll x) {
    ll l = lcm(a, b);

    ll s = x / a;
    ll t = x / b;
    ll u = x / lcm(a, b);

    return s + t - u;
  };

  ll l = 1, r = 1e18;
  while (r - l > 1) {
    ll m = (l + r) / 2;
    if (f(m) >= k) r = m;
    else l = m;
  }

  cout << r << endl;
  return 0;
}