#include <algorithm>
#include <array>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <string>
#include <vector>

#define FOR(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define FORR(i,l,n) for(int (i)=l;(i)<(int)(n);++(i))

int main() {
	const int Num = 3; //風船の数
	//風船の種類
	const std::string RED = "RED";
	const std::string BLUE = "BLUE";

	std::array<std::string, Num> ar;
	
	FOR(i, Num) {
		std::cin >> ar[i];
	}
	int count = std::count(begin(ar),end(ar),RED);
	if (count >= 2) {
		std::cout << RED << std::endl;
	}
	else{
		std::cout << BLUE << std::endl;
	}
	return 0;
}