#include <bits/stdc++.h>
using namespace std;
long long int const inf = 1e18;
long long int const maxn = 2e5 + 5;
long long int const mod = 1e9 + 7;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n, m, k;
  cin >> n >> m >> k;
  long long int l = 1, r = n * m, ans;
  while (l <= r) {
    long long int mid = (l + r) / 2;
    long long int cnt = 0;
    for (long long int i = 1; i <= n; i++) cnt += min((mid - 1) / i, m);
    if (cnt < k) {
      ans = mid;
      l = mid + 1;
    } else {
      r = mid - 1;
    }
  }
  cout << ans << "\n";
  ;
  return 0;
}
