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