#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  long long int n, k;
  cin >> n >> k;
  long long int arr[n];
  if (k > n) return cout << -1, 0;
  for (long long int i = 0; i < n; i++) cin >> arr[i];
  sort(arr, arr + n, greater<long long int>());
  cout << arr[k - 1] << " " << arr[k - 1];
}
