A round number is a number that ends with one or more zeros in a given base.
Let us define the roundness of a number in base as the number of zeros at the end of the base representation of . For example, has roundness in base , because the base representation of is , which ends with zeros.
Also define , the total roundness of a number , as the sum of the roundness of in base for all . For example, has roundness in base and roundness in base , , , , hence we get . You are also given .