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