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)

N = input()
l = ['3', '5', '7']
L = ['3', '5', '7']
temp = []
d = len(N)
N = int(N)


if N - 357 < 0:
    print(0)
    exit()

#d-1桁以下の753数
a = 0
for i in range(3, d):
    a += 3 ** i - 3 * (2 ** i - 2) - 3

#d桁の753数
for k in range(d - 1):
    for i in L:
        for j in l:
            temp.append(i + j)
    L.clear()
    L.extend(temp)
    temp.clear()
L = [i for i in L if '3' in i and '5' in i and '7' in i]

count = 0
for i in L:
    if int(i) <= N:
        count += 1
print(a + count)