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