#include <iostream>
#include <vector>
#include <deque>
#include <stack>
#include <memory>
#include <functional>
#include <algorithm>
#include <map>
#include <list>
#include <complex>
#include <string>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <numeric>
#include <array>
using namespace std;
typedef std::pair<int, int> pii;
typedef long long int ll;

#define pb push_back


int main(){
	
	long T, N, A;

	cin >> T;

	for (int i = 0; i < T; ++i) {
		cin >> N;
		std::vector<long> v;	
		std::vector<long> result;

		for (int j = 0; j < N; ++j) {
			cin >> A;
			v.pb(A);
		}
		sort(v.begin(), v.end());
		int pre_dif = 0;
		result.pb(v[0]);
		int pre_val = v[0];
		for (int i = 1; i < v.size(); ++i) {
			int dif = abs(v[i] - pre_val);
			if(dif > pre_dif){
				result.pb(v[i]);
				pre_val = v[i];
			}else if(dif == 0){
				if(v[i] != result[result.size()-2])
					result.pb(v[i]);
			}
			if(dif != 0){
			 	pre_dif = dif;
			}
		}

		for(const auto& element : result) {
			std::cout << element << " ";
		}
		std::cout << std::endl;
		std::cout << result.size() << std::endl;
	}


	return 0;
}