#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  long long n, m, k;
  cin >> n >> m >> k;
  long long l = 0, r = 1e12;
  while (r - l > 1) {
    long long i = n, t = 0, mid = (r + l) / 2;
    for (long long j = 1; j <= m; j++) {
      while (j * i > mid) {
        i--;
      }
      t += i;
    }
    if (t >= k) {
      r = mid;
    } else {
      l = mid;
    }
  }
  cout << l + 1;
  return 0;
}
