CF2162E

// Problem: E. Beautiful Palindromes
// Contest: Codeforces - Codeforces Round 1059 (Div. 3)
// URL: https://codeforces.com/contest/2162/problem/E
// Memory Limit: 256 MB
// Time Limit: 2000 ms
//
// Powered by CP Editor (https://cpeditor.org)

#include <assert.h>
#include <bits/stdc++.h>
using namespace std;
#ifndef __DEBUG__
#define dbg(...) 42
#endif
template <class T> using mpq = priority_queue<T, vector<T>, greater<T>>;

namespace rngs = std::ranges;
using ll = long long;
using a2l = array<ll, 2>;
using vl = vector<ll>;

void solve()
{
    ll n, k;
    cin >> n >> k;
    vl a(n);
    for (auto &x : a)
        cin >> x;
    set<ll> ss(a.begin(), a.end());
    vl opts;
    if (ss.size() + 2 <= n) {
        for (ll i = 1; i <= n && opts.size() < 3; ++i)
            if (ss.count(i) == 0)
                opts.push_back(i);
        if (opts.size() != 3)
            opts.push_back(a.back());
        dbg(opts);
    } else if (ss.size() + 1 == n) {
        ll x = -1, y = -1, z = a.back();
        for (ll i = 1; i <= n; ++i)
            if (ss.count(i) == 0)
                x = i;
        y = a[n - 1] == a[n - 2] ? a[n - 3] : a[n - 2];
        opts = vl{x, y, z};
        dbg(opts);
    } else {
        opts = vl{a[n - 3], a[n - 2], a[n - 1]};
        dbg(opts);
    }

    // cout << k << '\n';
    for (ll i = 0; i < k; ++i)
        cout << opts[i % 3] << ' ';
    cout << '\n';
}

int main(int argc, char **argv)
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    ll t = 1;
    cin >> t;
    while (t--)
        solve();

    return 0;
};