#include <iostream>
using namespace std;

int main() {
    string S1,S2,S3;
    cin>>S1>>S2>>S3;
    int red = 0;
    if (S1 == "RED") red++;
    if (S2 == "RED") red++;
    if (S3 == "RED") red++;
    if (red > 1) cout << "RED" << endl;
    else cout << "BLUE" << endl;
    return 0;
}