#include<iostream>
#include<string>
#include<cstring>
#include<complex>
#include<vector>
#include<algorithm>
using namespace std;

#define REP(i, j) for (int i = 0; i < (int)j; ++i)
#define FOR(i, j, k) for (int i = (int)j; i < (int)k; ++i)
#define SORT(v) sort(v.begin(), v.end())
#define REVERSE(v) reverse(v.begin(), v.end())
typedef complex<double> P;
typedef vector<int> VI;
typedef long long LL;
typedef pair<int,int> PII;

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	string r = "RED", b = "BLUE";
	int cnt = 0;
	REP(i,3) {
		string s;
		cin >> s;

		if (s == r) cnt++;
	}
	if (cnt >= 2) cout << r << endl;
	else cout << b << endl;

	return 0;
}