Problem:
Score : 300 points

Problem Statement

You are given an integer N. Among the integers between 1 and N (inclusive), how many Shichi-Go-San numbers (literally "Seven-Five-Three numbers") are there?

Here, a Shichi-Go-San number is a positive integer that satisfies the following condition:

When the number is written in base ten, each of the digits 7, 5 and 3 appears at least once, and the other digits never appear.

Constraints

1 \leq N < 10^9

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the number of the Shichi-Go-San numbers between 1 and N (inclusive).

Sample Input 1

575

Sample Output 1

4

There are four Shichi-Go-San numbers not greater than 575: 357, 375, 537 and 573.

Sample Input 2

3600

Sample Output 2

13

There are 13 Shichi-Go-San numbers not greater than 3600: the above four numbers, 735, 753, 3357, 3375, 3537, 3557, 3573, 3575 and 3577.

Sample Input 3

999999999

Sample Output 3

26484

Solution in Python (3.4.3) (judge verdict: Runtime Error)

n=input()
n_int = int(n)

if n_int<357:
  print(0)
else:
  counter__ = 0
  for k in range(3 ,len(n)+1):
    counter__ += recursive_f([])
    def recursive_f(A):
      if len(A) == k:
        A_ = int("".join(map(str,A)))
        counter = 0
        if len(set(A)) == 3 and A_ <= n_int:
          counter += 1
        return counter
      counter_ = 0
      for i in [3,5,7]:
        A.append(i)
        counter_ += recursive_f(A)
        A.pop()
      return counter_
        
print(counter__)