Description
This program calculates the total number of ways to select at most m different items from n distinct items. To accomplish this, define a function that computes the binomial coefficient C(n,m), which represents the number of ways to choose m items from n. Then, compute the sum:
For reference, the binomial coefficient C(n,m) is defined as:
where n! = 1 x 2 x 3 x ... x n
Input
Two integers n and m,
where 0<n<15 and 0<m≤n.
Output
One integer — the total number of ways to select up to m items from n distinct items.
Ensure that the output, including formatting 輸出格式, exactly matches the provided samples.