#include <bits/stdc++.h>

using namespace std;

#define REP(i, n) for(int i = 0; i < n; i++)

int main() {
    int counter = 0;
    REP(i, 3) {
        string s;
        cin >> s;
        if (s == "RED") counter++;
    }

    if (counter < 2) {
        cout << "BLUE" << endl;
    } else {
        cout << "RED" << endl;
    }

    return 0;
}