#include <bits/stdc++.h>

using namespace std;

const int N = 1005;

int p[N], f[N][N];
vector<int> G[N];

signed main() {
    int T; scanf("%d", &T);
    while (T--) {
        int n; scanf("%d", &n);
        vector< array<long long, 4> > E;
        for (int i = 1; i <= n; ++i) scanf("%d", &p[i]), G[i].clear();
        for (int i = 1, x, y; i < n; ++i) {
            scanf("%d%d", &x, &y), E.push_back({0, x, y, i}), G[x].push_back(y), G[y].push_back(x);
        }
        for (int i = 1; i <= n; ++i) {
            for (int j = 1; j <= n; ++j) f[i][j] = 1e9;
            f[i][i] = 0;
            queue<int> Q;
            Q.push(i);
            while (!Q.empty()) {
                int x = Q.front(); Q.pop();
                for (auto v : G[x]) {
                    if (f[i][v] > f[i][x] + 1) {
                        f[i][v] = f[i][x] + 1, Q.push(v);
                    }
                }
            }
        }
        vector< vector<int> > res;
        while (!is_sorted(p + 1, p + n + 1)) {
            for (auto &[a, b, c, d] : E) {
                a = 1ll * f[b][p[b]] * f[b][p[b]] + 1ll * f[c][p[c]] * f[c][p[c]] - 1ll * f[b][p[c]] * f[b][p[c]] - 1ll * f[c][p[b]] * f[c][p[b]];
            }
            sort(E.rbegin(), E.rend());
            bitset<N> vis;
            res.push_back({});
            for (auto [a, b, c, d] : E) {
                if  (vis[b] || vis[c] || a < 0) continue;
                vis[b] = vis[c] = 1, swap(p[b], p[c]);
                res.back().push_back(d);
            }
        }
        printf("%d\n", (int)res.size());
        for (auto x : res) {
            printf("%d", (int)x.size());
            for (auto v : x) printf(" %d", v);
            puts("");
        }
    }
    return 0;
}