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

int main(){
  map<string,int>mp;
  string s;
  for(int i=0;i<3;i++){
    cin>>s;
    mp[s]++;
  }
  if(mp["BLUE"]>=2){
    cout<<"BLUE"<<endl;
    return 0;
  }
  else{
    cout<<"RED"<<endl;
  }
  return 0;
}