#include <iostream>
#include <vector>
#include <unordered_map>
#include <string>
#include <map>
#include <cmath>
#include <algorithm>
#include <set>
#define ll long long
#define len(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define int long long
const ll maxn = 2e5 + 10;
const int logn = 20;
const ll inf = 1e15;
const int mod = 1e9 + 7;
using namespace std;

struct msk {
    ll cnt, maxw;
    bool operator==(msk v1) {
        return ((v1.cnt == cnt) && (v1.maxw == maxw));
    }
};

void solve() {
    int n, S; cin >> n >> S;
    vector<int> cost(n);
    for (int i = 0; i < n; ++i)
        cin >> cost[i];

    if (n == 1) {
        cout << "1\n1 1" << endl;
        return;
    }

    vector<msk> dp(1 << n, { n + 10, -100 });
    for (int i = 0; i < n; ++i) {
        dp[1ll << i].cnt = 1;
        dp[1ll << i].maxw = S - cost[i];
    }
    dp[0].cnt = 1;
    dp[0].maxw = S;



    for (int mask = 0; mask < (1ll << n); ++mask) {
        for (int i = 0; i < n; ++i) {
            if (!((mask >> i) & 1)) {
                if (dp[mask].maxw >= cost[i] && (dp[mask ^ (1ll << i)].cnt > dp[mask].cnt || (dp[mask ^ (1ll << i)].cnt == dp[mask].cnt && dp[mask ^ (1ll << i)].maxw < dp[mask].maxw - cost[i]))) {
                    dp[mask ^ (1ll << i)] = { dp[mask].cnt, dp[mask].maxw - cost[i] };
                }
                else if (dp[mask].maxw < cost[i] && (dp[mask ^ (1ll << i)].cnt > (dp[mask].cnt + 1) || (dp[mask ^ (1ll << i)].cnt == (dp[mask].cnt + 1) && dp[mask ^ (1ll << i)].maxw < S - cost[i]))) {
                    dp[mask ^ (1ll << i)] = { dp[mask].cnt + 1, S - cost[i] };
                }
            }
        }
    }


    int mask = (1ll << n) - 1;
    vector<int> p;
    while (mask > 1) {
        for (int i = 0; i < n; ++i) {
            if ((mask >> i) & 1) {
                int maskwi = mask ^ (1ll << i);
                msk v1 = { dp[maskwi].cnt, dp[maskwi].maxw - cost[i] };
                msk v2 = { dp[maskwi].cnt + 1, S - cost[i] };
                if (dp[mask] == v1 || dp[mask] == v2) {
                    p.push_back(i + 1);
                    mask = maskwi;
                    break;
                }
            }
        }
    }

    vector<vector<int>> ans;
    int curS = S;
    vector<int> tmp;
    for (int i = len(p) - 1; i >= 0; --i) {
        if (curS < cost[p[i] - 1]) {
            ans.push_back(tmp);
            tmp.clear();
            curS = S;
        }
        curS -= cost[p[i] - 1];
        tmp.push_back(p[i]);
    }
    if (len(tmp) > 0)
        ans.push_back(tmp);

    cout << len(ans) << endl;
    for (int i = 0; i < len(ans); ++i) {
        if (len(ans[i]) == 0) continue;
        cout << len(ans[i]) << " ";
        for (auto el : ans[i])
            cout << el << " ";
        cout << endl;
    }
}

signed main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t; cin >> t;
    while (t--) {
        solve();
    }
}