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: Accepted)

from sys import setrecursionlimit

setrecursionlimit(10**6)
def recur(N_:int,limit:int):
    if N_ > limit:
        return 0
    else:
        tmp = str(N_)
        if ("3" in tmp) and ("5" in tmp) and ("7" in tmp):
            N_ *= 10
            return recur(N_ + 3,limit) + recur(N_ + 5,limit) + recur(N_ + 7,limit) + 1
        else:
            N_ *= 10
            return recur(N_ + 3,limit) + recur(N_ + 5,limit) + recur(N_ + 7,limit)


def main():
    N = int(input())
    ans = recur(3,N) + recur(5,N) + recur(7,N)
    print(ans)
    return   

if __name__ == "__main__":
    main()