#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
bool check(long long x) {
  long long res = 0;
  for (long long i = 1; i <= n; i++) res += (min(m, x / i));
  if (res < k) return true;
  return false;
}
int main() {
  cin >> n >> m >> k;
  long long lo = 0, hi = n * m + 1;
  while (hi - lo > 1) {
    long long mid = (hi + lo) / 2;
    if (check(mid))
      lo = mid;
    else
      hi = mid;
  }
  cout << hi << endl;
  return 0;
}
