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