import sys
import math
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())
def NIJIGEN(H): return [list(input()) for i in range(H)]
def a(X):
    X_dumy = X
    out = ''
    while X_dumy>0:
        out = str(X_dumy%4)+out
        X_dumy = int(X_dumy/4)
    return out
N=int(input())
ans=0
if N<=10:
  print(0)
  exit()
if N<=99:
    print((N//3)-3)
    exit()
for i in range(16,262144):
  s=list(a(i))
  s="".join([str(3*int(i)) for i in s])
  s=int(s)
  if s<=N:
    ans+=1
print(ans+30)