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