P23235 [AtCoder] Almost Everywhere Zero
普及+
题目描述

Problem Statement

Find the number of integers between 1 and N (inclusive) that contains exactly K non-zero digits when written in base ten.

Input

Input is given from Standard Input in the following format:
N
K

Output

Print the count.

Constraints

  • $1 \leq N < 10^{100}$
  • $1 \leq K \leq 3$

Sample Input 1

100
1

Sample Output 1

19

The following 19 integers satisfy the condition:

  • 1,2,3,4,5,6,7,8,9,10,20,30,40,50,60,70,80,90,100

Sample Input 2

25
2

Sample Output 2

14

The following 14 integers satisfy the condition:

  • 11,12,13,14,15,16,17,18,19,21,22,23,24,25

Sample Input 3

314159
2

Sample Output 3

937

Sample Input 4

9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999
3

Sample Output 4

117879300

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
100 1
样例输出
19