<?php
$color1 = trim(fgets(STDIN));
$color2 = trim(fgets(STDIN));
$color3 = trim(fgets(STDIN));

$color_arr = array($color1, $color2, $color3);
$total = array_count_values($color_arr);

if ($total['RED'] > 1)
{
	echo "RED";
}
else
{
	echo "BLUE";
}