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: Time Limit Exceeded)

n = int(input())
sitigosan_list = [3, 5, 7]
count = 0

if n < 357:
    print(0)
    exit()

def make_753(num):
    b = str(num) + '3'
    c = str(num) + '5'
    d = str(num) + '7'
    sitigosan_list.append(int(b))
    sitigosan_list.append(int(c))
    sitigosan_list.append(int(d))


for i in sitigosan_list:
    make_753(i)
    if max(sitigosan_list) > n:
        break

for j in sitigosan_list:
    if '3' in str(j) and '5' in str(j) and '7' in str(j) and j <= n:
        count += 1

print(count)