from collections import deque
N = int(input())

l = [12, 15, 18, 21, 24, 27, 42, 45, 48, 51, 54, 57, 72, 75, 78, 81, 84, 87]
ans = -3
q = deque([3,6,9])
while len(q) > 0:
    num = q.popleft()
    if num <= N:
      ans += 1
      for y in [0, 3, 6, 9]:
          q.append(num*10 + y)

for i in l:
    if i <= N:
        ans += 1
print(ans)