import random

class bag():
    
    # constructor of the bag class
    def __init__(self, r, b, g):
        self.red = r
        self.blue = b
        self.green = g
        
    # The select method returns a ball from the bag, chosen
    # uniformly at random
    def select(self):
        total = self.red + self.blue + self.green
        ballIndex = random.randint(1, total)
        if ballIndex <= self.red:
            return "R"
        elif ballIndex <= self.red + self.blue:
            return "B"
        else:
            return "G"