#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, a[60], y;
  cin >> n >> k;
  for (int i = 0; i < n; i++) cin >> a[i];
  sort(a, a + n);
  for (int i = n - 1; i >= 0; i--) {
    y = a[i];
    k--;
    if (k == 0) break;
  }
  if (k != 0)
    cout << "-1\n";
  else
    cout << y << " " << y << endl;
  return 0;
}
