import math
import itertools

n = int(input())
k = int(input())

if (n < 99 and k == 3) or (n < 9 and k == 2):
    print(0) 

else:
    f = len(str(n))

    #f-1桁以内に収まる数

    en = 1
    for i in range(k):
        en *= f-1-i

    de = math.factorial(k)


    s = en // de * pow(9, k)

    #print(s)
    #f桁目によって絞る

    kami = int(str(n)[0])

    en_2 = 1
    for i in range(k-1):
        en_2 *= f-1-i

    de_2 = math.factorial(k-1)


    s += (en_2 // de_2 * pow(9, k-1)) * (kami-1)


    #以下上1桁は同じ数字

    keta = list(range(f-1))
    num = list(range(1,10))

    b =  kami * pow(10, f-1)
    m = 0

    if k == 1:
        s += 1
    elif k == 2:
        s += 9*(f-2) + int(str(n)[1])
    else:
        kami2 = int(str(n)[1])

        en_3 = (f-2)*(f-3)

        de_3 = 2


        s += (en_3 // de_3 * pow(9, k-1))  + kami2 * 9 * (f-2)

    print(s)