#include <bits/stdc++.h>
using namespace std;

int main() {
  string x;
  int r=0;
cin >>x;if (x =="RED")r++;
cin >>x;if (x =="RED")r++;
cin >>x;if (x =="RED")r++;
if(r>=2)cout << "RED" << endl;
else cout << "BLUE" << endl;
return(0);
}