/* vim: set ts=4 sts=4 sw=4 si foldmethod=marker: */
// {{{ stock programming challenge garbage

// IO
#include <string>
#include <iostream>
#include <iomanip>
#include <sstream>
#include <iterator>

// Utility
#include <cassert>
#include <algorithm>
#include <numeric>
#include <functional>
#include <cstdlib>
#include <cmath>

// Data structures
#include <vector>
#include <list>
#include <set>
#include <stack>
#include <queue>
#include <ext/hash_map>
#include <tr1/unordered_set>
#include <map>

// I want easy access to STL and things like hash_map
using namespace std;
using namespace std::tr1;
using namespace __gnu_cxx;

// Needed for hash_map<string/X>
namespace __gnu_cxx                                                                                 
{                                                                                             
    template<> struct hash<std::string>                                                       
    {                                                                                           
        size_t operator()(const std::string& x) const                                           
        {                                                                                         
            return hash<const char*>()(x.c_str());                                              
        }                                                                                         
    };                                                                                          
}     

typedef vector<int> vi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;

// }}}

void printPair(const pii& pair)
{
    if (pair.first < pair.second)
        cout << pair.first << " " << pair.second;
    else
        cout << pair.second << " " << pair.first;
    cout << endl;
}

int main()
{
    long cases;
    cin >> cases;
    while (cases--)
    {
        long people;
        cin >> people;
        vi source;
        vpii sends;
        vi returns;

        while (people--) 
        {
            vi::value_type temp;
            cin >> temp;
            source.push_back(temp);
        } 
        
        sort(source.begin(), source.end());

        int accumulated(0);

        while (source.size() >= 4)
        {
            int x1(source[0]), x2(source[1]), x3(source[source.size()-1]), x4(source[source.size()-2]);
            int sumStrategy1(max(x1, x4) + x1 + max(x1, x3) + x1),
                sumStrategy2(max(x1, x2) + x1 + max(x3, x4) + x2);
               
            if (sumStrategy1 < sumStrategy2)
            {
                sends.push_back(pii(x1, x4));
                sends.push_back(pii(x1, x3));
                returns.push_back(x1);
                returns.push_back(x1);
                accumulated += sumStrategy1;
            }
            else
            {
                sends.push_back(pii(x1, x2));
                returns.push_back(x1);
                sends.push_back(pii(x3, x4));
                returns.push_back(x2);
                accumulated += sumStrategy2;
            }
            source.erase(source.end()-2, source.end());
        }

        if (3 == source.size())
        {
            // special case, only happens if we had exactly 3 to start
            sends.push_back(pii(source[0], source[2]));
            returns.push_back(source[0]);
            sends.push_back(pii(source[0], source[1]));
            accumulated += accumulate(source.begin(), source.end(), 0);
        }
        else if (2 == source.size())
        {
            // remainder after 4+ 
            sends.push_back(pii(source[0], source[1]));
            accumulated += source[1];
        }
        
        if (1 == source.size())
        {
            // special case; only happens if we had exactly 1 to begin with
            cout << source[0] << endl << source[0] << endl;
        }
        else
        {
            cout << accumulated << endl;
            for (vi::size_type i(0); i < sends.size(); ++i)
            {
                printPair(sends[i]);
                if (i < returns.size())
                    cout << returns[i] << endl;
            }
        }
        if (cases) cout << endl;
    }

    return 0;
}