n = int(input())
k = int(input())
n_len = len(str(n))

x = [1]*(n_len)
for i in range(n_len-1):
    x[i+1] = x[i]*(i+1)

def calc(i,j):
    return x[i]/x[j]/x[i-j]*9**(j)

if n_len < k:
    print(0)
else:
    count = 0
    non_zero = 0
    for ind,i in enumerate(str(n)):
        if i != '0':
            non_zero += 1
            if n_len-ind-1 > k-non_zero:
                count += calc(n_len-ind-1,k-non_zero+1)
            if non_zero < k:
                count += calc(n_len-ind-1,k-non_zero)*(int(i)-1)
            elif non_zero == k:
                count += int(i)
                break
    
    print(int(count))