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 Kotlin (1.0.0) (judge verdict: Accepted)



fun main(args:Array<String>) {
    maxNum = readLine()!!.toLong()
    val ans = getAns(0,0)
    println(ans)
}


var maxNum:Long = 0
var set = mutableSetOf<Long>()

fun getAns(flag:Int, subtotal:Long):Long {
    if(subtotal > maxNum) {
        return 0
    }


    var ans:Long = 0
    if(flag == 7) {
        ans = 1
    }
    for(i in listOf(3,5,7)) {
        var newFlag = flag
        if(i == 3) {
            newFlag = (flag or 1)
        }
        if(i == 5) {
            newFlag = (flag or 2)
        }
        if (i == 7) {
            newFlag = (flag or 4)
        }
        val ret = getAns(newFlag, subtotal * 10 + i)
        ans += ret
    }
    return ans
}