#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m;
  long long k;
  cin >> n >> m >> k;
  if (k == 1)
    cout << 1 << '\n';
  else if (k == n * m)
    cout << n * m << '\n';
  else {
    long long left = 1;
    long long right = n * m;
    long long mid, now;
    while (left < right - 1) {
      mid = (left + right) / 2;
      now = 0;
      for (long long i = 1; i <= m; ++i) {
        now += min(n, mid / i);
      }
      if (now < k) {
        left = mid;
      } else {
        right = mid;
      }
    }
    cout << right << '\n';
  }
  return 0;
}
