Problem:
Score : 300 points

Problem Statement

You are given a string S consisting of digits between 1 and 9, inclusive.
You can insert the letter + into some of the positions (possibly none) between two letters in this string.
Here, + must not occur consecutively after insertion.

All strings that can be obtained in this way can be evaluated as formulas.

Evaluate all possible formulas, and print the sum of the results.

Constraints

1 \leq |S| \leq 10

All letters in S are digits between 1 and 9, inclusive.

Input

The input is given from Standard Input in the following format:

S

Output

Print the sum of the evaluated value over all possible formulas.

Sample Input 1

125

Sample Output 1

176

There are 4 formulas that can be obtained: 125, 1+25, 12+5 and 1+2+5. When each formula is evaluated,

125

1+25=26

12+5=17

1+2+5=8

Thus, the sum is 125+26+17+8=176.

Sample Input 2

9999999999

Sample Output 2

12656242944

Solution in Rust (1.15.1) (judge verdict: Accepted)

use std::io::Read;

fn main() {
    let mut buf = String::new();

    // 標準入力から全部bufに読み込む
    std::io::stdin().read_to_string(&mut buf).unwrap();

    // 行ごとのiterが取れる
    let mut iter = buf.split_whitespace();
    let input: String = iter.next().unwrap().parse().unwrap();

    let mut patterns = Vec::new();
    // '+' の位置のパターンをbit全探索で作る (そのため-1する)
    // 外側のループが全体のパターン数
    for i in 0..(1 << input.len() - 1) {
        let mut row = Vec::new();
        for j in 0..input.len() {
            // j桁右シフトして最初のbitが1かチェック
            if ((i >> j) & 1) == 1 {
                row.push(j);
            }
        }
        patterns.push(row);
    }

    let mut result = 0;
    for pattern in patterns {
        let mut left = 0;
        for right in pattern {
            let n: u64 = input[left..right + 1].parse().unwrap();
            result += n;
            left = right + 1;
        }
        let n: u64 = input[left..].parse().unwrap();
        result += n;
    }
    println!("{:?}", result);
}