atcoder#ABC154E. [ABC154E] Almost Everywhere Zero

[ABC154E] Almost Everywhere Zero

Score : 500500 points

Problem Statement

Find the number of integers between 11 and NN (inclusive) that contains exactly KK non-zero digits when written in base ten.

Constraints

  • 1N<101001 \leq N < 10^{100}
  • 1K31 \leq K \leq 3

Input

Input is given from Standard Input in the following format:

NN

KK

Output

Print the count.

100
1
19

The following 1919 integers satisfy the condition:

  • 1,2,3,4,5,6,7,8,9,10,20,30,40,50,60,70,80,90,1001,2,3,4,5,6,7,8,9,10,20,30,40,50,60,70,80,90,100
25
2
14

The following 1414 integers satisfy the condition:

  • 11,12,13,14,15,16,17,18,19,21,22,23,24,2511,12,13,14,15,16,17,18,19,21,22,23,24,25
314159
2
937
9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999
3
117879300