#include <bits/stdc++.h>
using namespace std;

typedef long long i64;

struct Stare {
    i64 sleft;
    i64 pmodif, puntil;
    int id; /// adica acum vreau sa modifi tipul care e pe poztia
                            ///pmodif si am voie sa il duc pana la puntil
    int last;
    bool operator< (const Stare & s) const {
        return sleft < s.sleft;
    }
};

vector <Stare> Solve(int nr, vector <i64> & vals, vector <i64> & spans, i64 smax, int & need, vector <pair <i64, i64>> & buffer)
{
    /// pun nr oameni
    vector <Stare> ans;
    priority_queue <Stare> stari;
    i64 sleft = smax - spans[nr - 1];

    //cerr << "VALS" << endl;
    //for (auto x : vals) cerr << x << " "; cerr << endl;

    if (sleft < 0)
        return vector <Stare> ();

    stari.push({ sleft, nr - 1, (i64)vals.size() - 1, nr - 1, -1 });

    while (!stari.empty()) {
        auto act = stari.top();
        stari.pop();
        ans.push_back(act), need--;
        buffer.push_back({ nr, smax - act.sleft });
        if (need == 0) break;

        //cerr << nr << " " << smax - act.sleft << endl;

        /// trebuie sa ma extind
        if (act.pmodif != act.puntil) {
            i64 nsleft = act.sleft - vals[act.pmodif + 1] + vals[act.pmodif];
            if (nsleft >= 0) {
                stari.push({ nsleft, act.pmodif + 1, act.puntil, act.id, ans.back().last });
            }
        }

        if (act.id != 0 && act.pmodif > act.id) {
            i64 nsleft = act.sleft - vals[act.id] + vals[act.id - 1];
            if (nsleft >= 0)
                stari.push({ nsleft, act.id, act.pmodif - 1, act.id - 1, (int)ans.size() - 1 });
        }
    }

    return ans;
}


vector <int> reconstruct(vector <Stare> & ans, vector <int> real, int k)
{
    vector <int> rez(k);
    /// plec de la ans.back()
    int poz = ans.size() - 1;

    for (int i = 0; i < k; ++i)
        rez[i] = real[i];

    while (poz != -1) {
        rez[ans[poz].id] = real[ans[poz].pmodif];
        // assert(ans[ans[poz].last].id == ans[poz].id + 1);
        poz = ans[poz].last;
    }

    return rez;

}

void test(int n, i64 k, int m, vector <i64> vals)
{
    vector <pair <i64, int>> for_sort(n);
    for (int i = 0; i < n; i++)
        for_sort[i] = { vals[i], i };
    sort(for_sort.begin(), for_sort.end());

    vector <int> real(n);
    for (int i = 0; i < n; i++)
        real[i] = for_sort[i].second;

    sort(vals.begin(), vals.end());
    vector <i64> spans = vals;
    for (int i = 1; i < n; i++)
        spans[i] += spans[i - 1];

    vector <Stare> ans;
    vector <pair <i64, i64>> buffer;

    int ch = 1;
    for (int i = n; i > 0 && m; i--) {
        ans = Solve(i, vals, spans, k, m, buffer);
        if (m == 0) {
            ch = i;
            break;
        }
    }

    cout << buffer.size() << '\n';
    for (auto i : buffer)
        cout << i.first << ' ' << i.second << '\n';
    if (buffer.size()) {
        auto x = reconstruct(ans, real, ch);
        for (auto i : x)
            cout << i + 1 << ' ';
        cout << '\n';
    }
}


int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t;
    cin >> t;

    while (t--) {
        i64 n, k, m;
        cin >> n >> k >> m;
        vector <i64> vals(n);
        for (auto & i : vals)
            cin >> i;

        test(n, k, m, vals);
    }
}