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

#define x first
#define y second
#define ir(x,a,b) ((a) <= (x) && (x) <= (b))
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define foru(i, n) for (int i = 0; i < n; ++i)
#define fori(i,a,n) for (int i = a; i < n; ++i)

// #ifdef LOCAL
// auto& operator<<(auto&, pair<auto, auto>);
// template<typename T, typename = T::value_type>
// auto& operator<<(auto& o, T x) requires (!same_as<T, string>) {
//   o << "{";
//   string s;
//   for (auto i : x) {
//     o << s << i;
//     s << ", ";
//   }
//   return o << "}";
// }
// auto& operator<<(auto& o, pair<auto, auto> p) {
//   return o << "(" << p.first << ", " << p.second << ")";
// }
// #define debug(x..) cerr << "["#x"]:",[](auto...$){((cerr<<" "<<$),...)<<endl;}(x)
// #else
// #define debug(...) 2137
// #endif

const int N = 25025;
int n, k;
int s[N];
int mx[6];

void solve() {
  cin >> n >> k;
  for (int i = 0; i < n - k + 1; i++) {
    cin >> s[i];
  }
  for (int i = 0; i < k; i++) {
    mx[i] = i;
    ll b = 0;
    ll pref = 0;
    for (int j = i + k; j < n; j += k) {
      // roznica aj - a(j - k)
      int d = s[j - k + 1] - s[j - k];
      pref += d;
      if (pref > b) {
        b = pref;
        mx[i] = j;
      } else if (pref == b) {
        cout << 0 << '\n';
        return;
      }
    }
  }
  /*for (int i = 0; i < k; i++) {
    cerr << i << ' ' << mx[i] << '\n';
  }*/
  
  vector<int> p(k);
  iota(p.begin(), p.end(), 0);
  vector<vector<int>> ans;
  do {
    vector<bool> used(n + 1);
    vector<int> x(n);
    bool ok = true;
    for (int i = 0; i < k; i++) {
      int a = n;
      while (used[a]) {
        a--;
      }
      int st = mx[p[i]];
      x[st] = a;
      used[a] = true;
      for (int j = st - k; j >= 0; j -= k) {
        ll b = x[j + k] + s[j] - s[j + 1];
        if (b < 1 || b > n || used[b]) {
          ok = false;
          break;
        }
        used[b] = true;
        x[j] = b;
      }
      for (int j = st + k; j < n; j += k) {
        ll b = x[j - k] + s[j - k + 1] - s[j - k];
        if (b < 1 || b > n || used[b]) {
          ok = false;
          break;
        }
        used[b] = true;
        x[j] = b;
      }
      if (!ok) {
        break;
      }
    }
    ll xs = 0;
    for (int i = 0; i < k; i++) {
      xs += x[i];
    }
    ok &= xs == s[0];
    if (ok) {
      ans.push_back(x);
    }
  } while (next_permutation(p.begin(), p.end()));
  sort(ans.begin(), ans.end());
  cout << ssize(ans) << '\n';
  for (auto& i : ans) {
   for (int j : i) {
     cout << j << ' ';
   }
   cout << '\n';
  }
}

int main() {
  ios_base::sync_with_stdio(false); cin.tie(nullptr);
  int t;
  cin >> t;
  while (t--) {
    solve();
  }
  return 0;
}