#include <bits/stdc++.h>
using namespace std;
int p[100005];
int main()
{
    int t;
    scanf("%d",&t);
    while (t--)
    {
        int n;
        scanf("%d",&n);
        for (int i=1;i<=n;i++)
        scanf("%d",&p[i]);
        vector<int> ans;
        for (int i=1;i<=n;i++)
        {
            if (i==1 || i==n || (p[i-1]<p[i])!=(p[i]<p[i+1]))
            ans.push_back(p[i]);
        }
        printf("%d\n",ans.size());
        for (int i:ans)
        printf("%d ",i);
        printf("\n");
    }
}