#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, k;
  cin >> n >> m >> k;
  long long l = 1, r = n * m;
  while (l != r) {
    long long mid = (l + r) / 2, num = 0;
    for (long long i = 1; i <= n; i++) {
      long long q = mid / i;
      if (q > m)
        num += m;
      else
        num += q;
    }
    if (num >= k)
      r = mid;
    else
      l = mid + 1;
  }
  cout << l << endl;
  return 0;
}
