N = input()
K = int(input())

if len(N) < K:
  print(0)
  exit()

ans = [1, int(N[-1]), 0, 0];

def combination(N,K):
  if N < K:
    return 0
  else:
    p = 1
    for k in range(K):
      p *= N
      N -= 1
    for k in range(1, K+1):
      p //= k
    return p

for k in range(1, len(N)):
  if int(N[-k-1]) > 0:
    a = [1, 0, 0, 0]
    for j in range(1, K+1):
      a[j] += (9**(j))*combination(k, j)
      a[j] += (int(N[-k-1])-1)*combination(k, j-1)*(9**(j-1)) + ans[j-1]
    ans = a
print(ans[K])