#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n, m, k;
  cin >> n >> m >> k;
  long long l = 0, r = n * m + 1;
  while (r - l > 1) {
    long long mid = (r + l) / 2;
    long long cnt = 0;
    for (long long i = 1; i <= n; i++) {
      cnt += min(m, mid / i);
    }
    if (cnt < k)
      l = mid;
    else
      r = mid;
  }
  cout << r << '\n';
  return 0;
}
