#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  int arr[n];
  for (int i = 0; i < n; i++) cin >> arr[i];
  sort(arr, arr + n);
  if (n == k)
    cout << arr[0] << " " << arr[0] << endl;
  else if (n < k)
    cout << -1 << endl;
  else {
    cout << arr[n - k - 1] + 1 << " " << arr[n - k - 1] + 1 << endl;
  }
  return 0;
}
