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 .
Find . Give your answer modulo .
Write-up coming later
The complete problem is available here. An approach, code, and answer will be added later.