#include <bits/stdc++.h>
using namespace std;
int md(int n) {
  if (n < 0) n *= -1;
  return n;
}
int main() {
  int a[500], n, k, l;
  cin >> n >> k;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  if (n < k)
    cout << "-1";
  else {
    sort(a, a + n);
    cout << a[n - k] << " " << a[n - k] << endl;
  }
  return 0;
}
