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#include<bits/stdc++.h>
#define EDGE pair<int, int>
#define f first
#define s second
using namespace std;
constexpr int MAXN = 1e3 + 7;
constexpr int MAXM = 3e3 + 7;

bitset <MAXN> canbe;

set <EDGE> edges; // <a, b> in edges <=> a < b
int ok;
int ook;

bitset <MAXN> used;
vector <int> graf[MAXN];

void rmv(int w)
{
    used[w] = true;
    for (int i : graf[w]){
        if (used[i]) continue;
        edges.erase({min(i, w), max(i, w)});
    }
}

void add(int w)
{
    used[w] = false;
    for (int i : graf[w]){
        if (used[i]) continue;
        edges.insert({min(i, w), max(i, w)});
    }
}

bool exists(int ck) // set ok and edges before using
{
    if (edges.size() == 0) return true;
    if (edges.size() >= ck * ook) return false;

    EDGE e = *edges.begin();

    rmv(e.f);
    bool res = exists(ck-1);
    add(e.f);

    if (res) return true;

    rmv(e.s);
    res = exists(ck-1);
    add(e.s);

    return res;
}

bool ex_mark(int ck)
{
    if (edges.size() == 0) return true;
    if (edges.size() >= ck * ook) return false;

    EDGE e = *edges.begin();

    if (canbe[e.f]) swap(e.f, e.s);

    rmv(e.f);
    bool res = exists(ck-1);
    add(e.f);

    if (res) canbe[e.f] = true;

    bool res2 = false;
    if (!res || !canbe[e.s]){
        rmv(e.s);
        res2 = exists(ck-1);
        add(e.s);

        if (res2) canbe[e.s] = true;
    }

    return res || res2;
}

void cleanv(vector<int>& v)
{
    vector <int> empt;
    swap(v, empt);
}

void clean()
{
    used = 0;
    canbe = 0;
    for (int i = 0; i < MAXN; i++)
        cleanv(graf[i]);

    set <EDGE> emptset;
    swap(edges, emptset);
}

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

    int tcase;
    cin >> tcase;

    while (tcase--)
    {
        clean();

        int n, m, k;
        cin >> n >> m >> k;

        vector <int> deg(n + 1);
        for (int i = 0; i <= n; i++) deg[i] = 0;

        for (int i = 0; i < m; i++){
            int a, b;
            cin >> a >> b;
            graf[a].push_back(b);
            graf[b].push_back(a);
            deg[a]++;
            deg[b]++;

            edges.insert({min(a, b), max(a, b)});
        }

        ok = k;
        ook = k;
        for (int i = 1; i <= n; i++){
            if (deg[i] > ook){
                ok--;
                rmv(i);
                canbe[i] = true;
            }
        }

        if (ok < 0 || !exists(ok))
        {
            cout << "-1\n";
            continue;
        }

        while (exists(ok - 1))
            ok--;

        cout << ok << " ";


        // odzysk wynik
        vector <int> v;
        for (int i = 1; i <= n; i++){
            if (canbe[i]){
                v.push_back(i);
                continue;
            }
            rmv(i);
            if (ex_mark(ok - 1))
                v.push_back(i);
            add(i);
        }

        cout << v.size() << "\n";
        for (int i : v)
            cout << i << " ";
        cout << "\n";
    }

    return 0;
}