import std.stdio, std.string, std.algorithm, std.range;

void main(){
    int red=0;
    auto color = iota(3).map!(_ => readln.chomp).array;
    foreach(i; 0 .. 3) {
        if(color[i] == "RED") red++;
    }
    writeln(red >= 2 ? "RED" : "BLUE");
}