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

signed main() {
    cin.tie(nullptr)->sync_with_stdio(false);

    int tests;
    cin >> tests;
    while (tests--) {
        int n;
        cin >> n;
        int a, b, c;
        cin >> a >> b >> c;
        --a, --b, --c;
        vector<vector<int>> g(n);
        for (int  i = 0; i < n - 1; ++i) {
            int u, v;
            cin >> u >> v;
            --u, --v;
            g[u].push_back(v);
            g[v].push_back(u);
        }
        vector<int> da(n), db(n), dc(n);
        auto calc_dist = [&](auto calc_dist, int u, int p, vector<int>& d) -> void {
            for (auto to : g[u]) {
                if (to != p) {
                    d[to] = d[u] + 1;
                    calc_dist(calc_dist, to, u, d);
                }
            }
        };
        calc_dist(calc_dist, a, -1, da);
        calc_dist(calc_dist, b, -1, db);
        calc_dist(calc_dist, c, -1, dc);
        string res = "DRAW";
        for (int iter = 0; iter < 3; ++iter) {
            vector<int> can(n);
            vector<int> par(n, -1);
            can[c] = true;
            auto dfs = [&](auto dfs, int u, int p) -> void {
                par[u] = p;
                for (auto to : g[u]) {
                    if (to != p) {
                        if (can[u]) can[to] = 1;
                        dfs(dfs, to, u);
                    }
                }
            };
            dfs(dfs, a, -1);
            auto dfs2 = [&](auto dfs2, int u, int p) -> void {
                par[u] = p;
                for (auto to : g[u]) {
                    if (to != p) {
                        dfs2(dfs2, to, u);
                        can[u] += can[to];
                    }
                }
            };
            dfs2(dfs2, a, -1);
            vector<bool> used(n, false);
            int b_ = b;
            used[b] = can[b];
            while (par[b] != -1) {
                if (can[par[b]] > can[b]) used[par[b]] = true;
                b = par[b];
            }
            b = b_;
            bool ok = false;
            for (int i = 0; i < n; ++i) {
                if (!used[i]) continue;
                ok |= da[i] >= db[i] - (iter == 2);
            }
            if (!ok) {
assert(res == "DRAW");
                res = char('A' + iter);
            }
            swap(da, dc);
            swap(da, db);
            swap(a, c);
            swap(a, b);
        }
        cout << res << '\n';
    }
}