import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.NavigableSet;
import java.util.TreeSet;

import static java.lang.Integer.parseInt;

/**
 * Created by bugkiller on 11/03/19.
 */
class KthLargestElementInStream {

    private static final int a[] = new int[1000000];

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int t, n, k;
        String s[];
        t = parseInt(br.readLine());
        while (t-- > 0) {
            s = br.readLine().split("\\s");
            k = parseInt(s[0]);
            n = parseInt(s[1]);
            s = br.readLine().split("\\s");
            for (int i = 0; i < n; i++) {
                a[i] = parseInt(s[i]);
            }
            System.out.println(convertToString(kthLargest(a, n, k), n));
        }
    }

    static int[] kthLargest(int a[], int n, int k) {
        NavigableSet<Integer> set = new TreeSet<>();
        int result[] = new int[n];
        for (int i = 0; i < n; i++) {
            if (i < k) {
                set.add(a[i]);
            } else {
                if (a[i] > set.first()) {
                    set.pollFirst();
                    set.add(a[i]);
                }
            }
            if (i < k - 1) {
                result[i] = -1;
            } else {
                result[i] = set.first();
            }
        }
        return result;
    }

    private static String convertToString(int a[], int n) {
        StringBuilder sbr = new StringBuilder();
        for (int i = 0; i < n; i++) {
            sbr.append(a[i]).append(" ");
        }
        sbr.deleteCharAt(sbr.length() - 1);
        return sbr.toString();
    }
}