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