#include <bits/stdc++.h>
using namespace std;
int n, m;
long long k;
bool cnt(long long mid) {
  long long c = 0;
  for (int i = 1; i <= n; ++i) {
    c += min(1ll * m, mid / i);
  }
  return c < k;
}
int main() {
  scanf("%d%d%lld", &n, &m, &k);
  long long st = 0;
  long long en = 1ll * n * m;
  while (st < en) {
    long long mid = (st + en + 1) >> 1;
    if (cnt(mid)) {
      st = mid;
    } else {
      en = mid - 1;
    }
  }
  printf("%lld", st + 1);
  return 0;
}
