#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  ll a, b, k;
  cin >> a >> b >> k;
  ll l = lcm(a, b);
  ll ok = 0, ng = 1e18;
  while (ng - ok > 1) {
    ll x = (ok + ng) / 2;
    ll cnt = x / a + x / b - x / l;
    (cnt < k ? ok : ng) = x;
  }
  cout << ok + 1 << '\n';
  return 0;
}