#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 5;
const long long len = 400;
const long long INF = 1e9 + 5;
const long long mod = 1e9 + 7;
long long n, m, k;
long long calc(long long x) {
  long long res = 0;
  for (long long i = 1; i <= n; i++) res += min(m, (x - 1) / i);
  return res;
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> m >> k;
  long long l = 1, r = n * m;
  while (l != r) {
    long long mid = (l + r + 1) >> 1;
    if (calc(mid) < k)
      l = mid;
    else
      r = mid - 1;
  }
  cout << l << "\n";
}
