#include<bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;

int dis[N];
vector<int> adj[N];
int par[N];
void dfs(int ind, int p, int d = 0){
    par[ind] = p;
    dis[ind] = d;
    for(auto x : adj[ind]){
        if(x == p)continue;
        dfs(x, ind, d + 1);
    }
}

int lca(int a, int b){
    while(a != b){
        if(dis[a] > dis[b])a = par[a];
        else b = par[b];
    }
    return a;
}
void testcase(int cs){
    int n;
    cin >> n;
    for(int i = 1; i <= n; ++i)adj[i].clear();
    int a, b, c;
    cin >> a >> b >> c;

    for(int i = 1; i < n; i++){
        int x, y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }


    for(auto x : adj[a]){
        if(x == c){
            cout << "A\n";
            return;
        }
    }

    dfs(a, -1);

    int l = lca(b, c);

    dfs(l, -1);

    vector<pair<int, int>> v;
    v.emplace_back(dis[a], 0);
    v.emplace_back(dis[b], 1);
    v.emplace_back(dis[c], 2);


    sort(v.begin(), v.end());
    if(v.back().first == v[0].first){
        cout << "DRAW\n";
        return;
    }
    string s = "ABC";
    if(v[0].first == v[1].first){
        if((v[0].second + 1) % 3 == v[1].second){
            cout << s[v[1].second] << "\n";
        }else{
            cout << s[v[0].second] << "\n";
        }
        return;
    }
    cout << s[v[0].second] << "\n";
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    int T = 1;
    cin >> T;
    for(int cs = 1; cs <= T; ++cs){
        testcase(cs);
    }
}