Champernowne Count

문제

The $nn$th Champernowne word is obtained by writing down the first $nn$ positive integers and concatenating them together. For example, the 10th Champernowne word is "12345678910".

Given two positive integers $nn$ and $kk$, count how many of the first $nn$ Champernowne words are divisible by $kk$.

입력

The single line of input contains two integers, $nn$ $(1\le n\le {10}^5)(1\; \backslash le\; n\; \backslash le\; 10^5)$ and $kk$ $(1\le k\le {10}^9)(1\; \backslash le\; k\; \backslash le\; 10^9)$.

출력

Output a single integer, which is a count of the first $nn$ Champernowne words divisible by $kk$.