#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>
//---------------------------
using namespace std;
//---------------------------
#define REP(i,n) for(int i = 0; i < (n); i++)
#define P(x) cout << (x) << "\n"
//---------------------------


int main(){
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);


  int cnt = 0;
  REP(i,3){
    string s;cin >>s;
    if (s == "RED") {
      cnt++;
    }
  }
  cout << (cnt > 1 ? "RED" : "BLUE") << "\n";


  return 0;
}