#include <bits/stdc++.h>
using namespace std;
long long n, m, k;
long long p(long long x) {
  long long temp = 0;
  for (long long i = 1; i <= n; i++) {
    temp += min((x - 1) / i, m);
  }
  if (temp < k) return 1;
  return 0;
}
int32_t main() {
  cin >> n >> m >> k;
  long long l = 1, r = n * m;
  while (l < r) {
    long long mid = (l + r + 1) / 2;
    if (p(mid))
      l = mid;
    else
      r = mid - 1;
  }
  cout << l;
}
