#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, k;
  int A[100];
  cin >> n >> k;
  for (int i = 0; i < n; i++) {
    cin >> A[i];
  }
  if (k > n) {
    cout << -1 << endl;
    return 0;
  }
  sort(A, A + n);
  reverse(A, A + n);
  cout << A[k - 1] << " " << A[k - 1] << endl;
  return 0;
}
