#include <iostream>
#include <string>

using namespace std;

int main() {
	string s;

	int red = 0;
	for (int i = 0; i < 3; i++) {
		cin >> s;
		if (s == "RED") {
			red++;
		}
	}

	cout << (red > 1 ? "RED" : "BLUE") << endl;
	return 0;
}