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

const int N=2e5+1e3+7;

int T,n,pos[3];

vector<int> g[N];

int mn[N*2][21],anc[N][21];

int seq[N],dc,st[N],fa[N],dep[N];

void dfs(int x,int f)
{
    anc[x][0]=f;
    for(int j=1;j<=20;j++)
        anc[x][j]=anc[anc[x][j-1]][j-1];
    dep[x]=dep[f]+1;
    fa[x]=f;
    seq[++dc]=x;
    st[x]=dc;
    mn[dc][0]=st[x];
    for(auto v:g[x])
    {
        if(v==f)
            continue;
        dfs(v,x);
        seq[++dc]=x; 
        mn[dc][0]=st[x];
    }
}

int lca(int x,int y)
{
    x=st[x],y=st[y];
    if(x>y)
        swap(x,y);
    int k=__lg(y-x+1);
    return seq[min(mn[x][k],mn[y-(1<<k)+1][k])];
}

int find(int x,int y)
{
    int p=lca(x,y);
    if(p!=x)
        return fa[x];
    else
    {
        int t=dep[y]-dep[x]-1;
        while(t)
        {
            int k=__builtin_ctz(t);
            t-=1<<k;
            y=anc[y][k];
        }
        return y;
    }
}

int go(int t)
{
    int x=pos[t],y=pos[(t+2)%3];
    int p=find(x,y);
    int z=pos[(t+1)%3];
    if(p==z||p==fa[z]||z==fa[p])
        return x;
    return p;
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>T;
    while(T--)
    {
        cin>>n;
        for(int i=0;i<3;i++)
            cin>>pos[i];
        for(int i=1;i<=n;i++)
            g[i].clear();
        for(int i=1;i<n;i++)
        {
            int u,v;
            cin>>u>>v;
            g[u].push_back(v);
            g[v].push_back(u);
        }
        dc=0;
        dfs(1,0);
        for(int j=1;j<=20;j++)
            for(int i=1;i+(1<<j)-1<=dc;i++)
                mn[i][j]=min(mn[i][j-1],mn[i+(1<<(j-1))-1][j-1]);
        int t=0;
        int round=n*3+10;
        while(round--)
        {
            int p=go(t);
            pos[t]=p;
            if(pos[t]==pos[(t+2)%3])
            {
                cout<<"ABC"[t]<<"\n";
                break;
            }
            t=(t+1)%3;
        }
        if(round<0)
            cout<<"DRAW\n";
    }
}