import math
import sys

def resolve():
    nstr = input()
    length = len(nstr)
    n = int(nstr)

    if length == 2:
        print(n//3-3)
        return

    result = 30
    
    if length - 3 > 0:
        result += 16*(4**(length-3)-1)

    head = int(nstr[0])
    result += (head-1)//3 * 4**(length-1)
    if head%3 != 0:
        print(result)
        return

    for i, c in zip(range(length-1,0,-1),nstr[1:]):
        if int(c) == 0: continue
        result += (int(c)+2)//3 * 4**(i-1)

        if int(c)%3 != 0: break

    else:
        result += 1

    print(result)

resolve()