101544: [AtCoder]ABC154 E - Almost Everywhere Zero

Memory Limit:256 MB Time Limit:2 S
Judge Style:Text Compare Creator:
Submit:0 Solved:0

Description

Score : $500$ points

Problem Statement

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

Constraints

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

Input

Input is given from Standard Input in the following format:

$N$
$K$

Output

Print the count.


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

Input

题意翻译

给定两个正整数 $N,K$,求出 $1$ 到 $N$ 中有多少个正整数,满足它的非零数位个数和恰好等于 $K$。 $1 \le N < 10^{100}$,$1 \le K \le3$。

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