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