import random

class twoDice():
    
    # constructor
    def __init__(self, a = 6, b = 6):
        self.sides1 = a
        self.sides2 = b
        self.previousRolls = []
        
    # Method that rolls the two dice and returns the sum of the outcomes  
    def roll(self):
        (self.previousRolls).append(random.randint(1, self.sides1) + random.randint(1, self.sides2))
        # return self.previousRolls[-1]
        return self.mostRecentRoll()
    
    # return the value of the most recent roll
    def mostRecentRoll(self):
        return self.previousRolls[-1]
    
    # returns the list consisting of the most recent n rolls 
    def previousRoll(self, n):
        return self.previousRolls[len(self.previousRolls)-n:]
    
    # returns the average roll value based on all the rolls thus far
    def meanRoll(self):
        return sum(self.previousRolls)*1.0/len(self.previousRolls)