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