import math

def comb(n, r):
    return math.factorial(n) // (math.factorial(n - r) * math.factorial(r))

def count1(nrow, k):
  keta = len(nrow)
  topmax = int(nrow[0])

  if keta == 1:
    return topmax
  ans = topmax
  ans += (keta-1)*9
  return ans

def count2(nrow, k):
  keta = len(nrow)
  topmax = int(nrow[0])

  ans = count1(nrow[1:], k)  # top==topmax
  ans += (topmax-1)*(keta-1)*9  # top!=topmax
  if keta > 2:
    ans += comb(keta-1, 2)*81
  return ans

def count3(nrow, k):
  keta = len(nrow)
  topmax = int(nrow[0])

  ans = count2(nrow[1:],k) #top==topmax
  ans += (topmax-1)*comb(keta-1,2) * 81#top!=topmax
  if keta > 3:
    ans += comb(keta-1 , 3) * 729
  return ans

nrow=input()
k = int(input())

if k==1:
  print(count1(nrow,k))
elif k == 2:
  print(count2(nrow,k))
elif k == 3:
  print(count3(nrow,k))
