#include<bits/stdc++.h>
using namespace std;
typedef long long int uli;
int main(){
  int t;
  cin>>t;
  while(t--){
    int n;
    string s,v;
    cin>>n>>s;
    int moves[2]={0,0};
    string players[2]={"Dee","Dum"};
    for(int i=0;i<n;i++){
      string w;
      cin>>w;
      int c=0;
      for(char ch:w)c+=(ch==w[0]);
      int idx=(w[0]-'0');
      moves[idx]+=c;
    }
    if(s!=players[0]){
      swap(moves[0],moves[1]);
      swap(players[0],players[1]);
    }
    string ans="";
    if(moves[1]>=moves[0])ans=players[1];
    else ans=players[0];
    cout<<ans<<endl;
  }
  return 0;
}