#include <iostream>
#include <string>
using namespace std;
int main(){
	string St1,St2,St3;
	cin>>St1>>St2>>St3;
	int red=0,blue=0;
	if(St1=="RED"){
		red++;
	}else{
		blue++;
	}
	if(St2=="RED"){
		red++;
	}else{
		blue++;
	}
	if(St3=="RED"){
		red++;
	}else{
		blue++;
	}
	if(red>1){
		cout<<"RED"<<endl;
	}else{
		cout<<"BLUE"<<endl;
	}
	return 0;
}