su = 0
m = int(input())
numOfZeros = int(input())
for i in range(1,m +1):
    num = i
    currZeros = 0
    while(i>=10):
    	if num % 10 == 0:
   		    currZeros += 1
    	num /= 10

    if currZeros == numOfZeros:
    	su += 1
print(su)
    