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 JavaScript (Node.js 12.16.1) (judge verdict: Accepted)

function Main(input){
    const N = input.trim();
    const array = ['3', '5', '7'];
    let answer = 0;
    const DFS = (N, num753) => {
        // 753の数値を含んでいるかチェック
        const contains357 = array.map(val => num753.includes(val)).reduce((a, b) => a && b);
        // 桁数上限に達成
        if(N.length == num753.length){
            if(contains357 && Number(num753) <= Number(N)) answer++;
            return; 
        }
        // 現在の数値をチェック
        if(contains357 && Number(num753) <= Number(N)) answer++;
        // 3,5,7を入れていく
        array.forEach(val => DFS(N, num753 + val));
    }
    // 一桁目を入れる
    array.forEach(val => DFS(N, val));
    console.log(answer);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));