AT_abc444_b [ABC444B] Digit Sum

The **digit sum** of a positive integer $ n $ is defined as the sum of the digits when $ n $ is represented in decimal. For example, the digit sum of $ 2026 $ is $ 2+0+2+6=10 $ . Find the number of positive integers not exceeding $ N $ whose digit sum is $ K $ .

The input is given from Standard Input in the following format: > $ N $ $ K $

Output the answer.

### Sample Explanation 1 Among the positive integers not exceeding $ 30 $ , there are three integers whose digit sum is $ 4 $ : $ 4,13,22 $ . ### Constraints - $ 1\leq N,K \leq 10^5 $ - All input values are integers.