In a bag of three marbles, there are exactly two blue marbles. If Kia randomly chooses two marbles without replacement, the probability of choosing the two blue marbles is one-third. However, before Kia chooses her two marbles, additional marbles are added to the bag. The probability of picking two blue marbles without replacement is still one-third. What is the least number of marbles that could be in the bag after the additional marbles have been added?
