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