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: Wrong Answer)

#coding: utf-8
from collections import Counter
N = int(input())
l = ["0", "3", "5", "7"]
ans = ["0" for _ in range(9)]
cnt = 0
for a in l:
    ans[0] = a
    for b in l:
        ans[1] = b
        for c in l:
            ans[2] = c
            for d in l:
                ans[3] = d
                for e in l:
                    ans[4] = e
                    for f in l:
                        ans[5] = f
                        for g in l:
                            ans[6] = g
                            for h in l:
                                ans[7] = h
                                for i in l:
                                    ans[8] = i
                                    ans_c = Counter(ans)
                                    ans_i = int("".join(ans))
                                    #if ans_i <= N and sum([l[j] in str(ans_i) for j in range(len(l))]) == 3 and len(ans_c.values()) == 3:
                                    if ans_i <= N and "0" not in str(ans_i) and len(ans_c.keys()) == 4 and len(str(ans_i)) >= 3:
                                        cnt += 1
print(cnt)