#include <iostream>

#include <algorithm>

#include <cstdio>

#include <cmath>

#include <stack>

#include <vector>

using namespace std;

#define LL long long

const int N = ;

vector<LL> arr;

bool vis[N];

void solve()

{

    while (true)

    {

        fill(vis, vis + arr.size(), );

        bool f = true;

        for (int i = ; i < arr.size(); i++)

        {

            if (i >  && arr[i] < arr[i - ])

            {

                vis[i - ] = vis[i] = ;

                f = false;

            }

            if (i < arr.size() -  && arr[i] > arr[i + ])

            {

                vis[i + ] = vis[i] = ;

                f = false;

            }

        }

        if (f)break;

        for (int i = arr.size() - ; i >= ; i--)

        {

            if (vis[i])arr.erase(arr.begin() + i);

        }

    }

}

int main()

{

    freopen("in.txt", "r", stdin);

    freopen("outstd.txt", "w", stdout);

    cin.sync_with_stdio(false);

    LL t, n;

    cin >> t;

    while (t--)

    {

        int id;

        cin >> id;

        cout << id<<':' << endl;

        cin >> n;

        arr.clear();

        for (int i = ; i < n; i++)

        {

            LL num;

            cin >> num;

            arr.push_back(num);

        }

        solve();

        cout << arr.size() << endl;

        for (int i = ; i < arr.size(); i++)

            cout << arr[i] << ' ';

        cout << endl;

    }

}