#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()

using namespace std;
using ll = long long;

const int N = 25000;

void Solve() {
    int n, k;
    cin >> n >> k;
    vector<int> a(n - k + 1);
    for (int i = 0; i < a.size(); i++) {
        cin >> a[i];
    }
    bitset<2 * N> tot;
    for (int i = 0; i < n; i++) tot[i] = 1;
    bitset<2 * N> cur;
    vector<vector<ll>> dlts;
    for (int i = 0; i < k; i++) {
        dlts.push_back({0});
    }
    for (int i = 1; i < n - k + 1; i++) {
        dlts[(i - 1) % k].push_back(dlts[(i - 1) % k].back() + a[i] - a[i - 1]);
    }
    for (int i = 0; i < k; i++) {
        ll dlt = *min_element(all(dlts[i]));
        for (ll& val : dlts[i]) val -= dlt;
        if (*max_element(all(dlts[i])) >= n || *min_element(all(dlts[i])) < 0) {
            cout << "0\n";
            return;
        }
    }
    vector<int> per;
    vector<bitset<2 * N>> arr(k);
    for (int i = 0; i < k; i++) {
        for (int val : dlts[i]) {
            arr[i][val] = 1;
        }
    }
    for (int i = 0; i < k; i++) per.push_back(i);
    vector<vector<int>> ans;
    do {
        cur.reset();
        vector<int> dlt2;
        for (int i = 0; i < k; i++) {
            for (int j = 0; j < n; j++) {
                if (cur[j] == 0) {
                    cur |= arr[per[i]] << j;
                    dlt2.push_back(j);
                    break;
                }
            }
        }
        if ((cur & tot).count() == n) {
            vector<int> curans(n);
            for (int i = 0; i < k; i++) {
                int curind = per[i];
                for (int j = 0; j < dlts[curind].size(); j++) {
                    curans[j * k + curind] = dlts[curind][j] + dlt2[i];
                }
            }
            for (int j = 0; j < n; j++) {
                cur[curans[j]] = 0;
            }
            if (cur.count() == 0 && *max_element(all(curans)) < n && accumulate(curans.begin(), curans.begin() + k, 0LL) + k == a[0]) {
                ans.push_back(curans);
            }
        }
    } while(next_permutation(all(per)));
    cout << ans.size() << "\n";
    sort(all(ans));
    for (auto& v : ans) {
        for (int val : v) {
            cout << val + 1 << " ";
        }
        cout << '\n';
    }
}


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int q;
    cin >> q;
    while (q--) {
        Solve();
    }
}