#include <bits/stdc++.h>
#define pb push_back
#define int int64_t
#define pii pair<int, int>
#define X first
#define Y second
#define all(x) (x).begin(),(x).end()
#define lb lower_bound
#define ub upper_bound

using namespace std;

const int inf = 1e18;

void p(auto A){
	for(auto e : A)cout << e << ' ';
	cout << '\n';
}

void solve(){
	int n; cin >> n;
	int sa, sb, sc; cin >> sa >> sb >> sc;
	sa--; sb--; sc--;
	vector<vector<int>>g(n);
	for(int i = 0; i< n-1; i++){
		int c, d; cin >> c >> d;
		c--; d--;
		g[c].pb(d);
		g[d].pb(c);
	}
	
	int rt = -1;
	auto dfs1 = [&](auto&& self, int u, int p)->int{
		int ret = 0;
		for(auto v : g[u])if(v!=p)ret+=self(self, v, u);
		if(u == sb || u == sc)ret++;
		if(rt == -1 && ret == 2)rt = u;
		return ret;
	};
	dfs1(dfs1, sa, sa);
	
	assert(rt != -1);
	
	vector<int>dis(n);
	auto dfs2 = [&](auto&& self, int u, int p)->void{
		for(auto v : g[u])if(v!=p){
			dis[v] = dis[u]+1;
			self(self, v, u);
		}
	};
	dfs2(dfs2, rt, rt);
	
	if(dis[sa] < dis[sb] && dis[sa] <= dis[sc]+1){
		cout << "A\n";
		return;
	}
	if(dis[sb] < dis[sc] && dis[sb] <= dis[sa]){
		cout << "B\n";
		return;
	}
	if(dis[sc]+1 < dis[sa] && dis[sc] <= dis[sb]){
		cout << "C\n";
		return;
	}
	cout << "DRAW\n";
}
	

signed main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	int t = 1;
	cin >> t;
	while(t--)solve();
}


//freopen(".in", "r", stdin);
//freopen(".out", "w", stdout);