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 Java (OpenJDK 1.8.0) (judge verdict: Accepted)


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.*;

public class Main {

    static String z;
    static long sum=0;


    public static void main(String[] args) throws IOException {
        Scanner s = new Scanner(System.in);
        String word = s.next();
        z="";
        int n = word.length()-1;
        for(int i=0;i<word.length();i++){
            if(i!=word.length()-1)z+=word.charAt(i)+" ";
            else z+=word.charAt(i);
        }

        solve(0,n,"");


        System.out.println(sum);

    }

    public static void solve(int start, int n,String acc){
        if(start==n){
            String res="";
            for(int i=0,j=0;i<z.length();i++){
                if(z.charAt(i)==' '){
                    if(acc.charAt(j++)=='+')res+='+';
                }
                else res+=z.charAt(i);
            }

            String ac = "";
            for(int i=0;i<res.length();i++){
                if(res.charAt(i)=='+'){
                    sum+= Long.parseLong(ac);
                    ac="";
                }
                else {
                    ac+=res.charAt(i);
                }
            }
            sum+= Long.parseLong(ac);

        }
        
        else{
            solve(start+1,n,acc+" ");
            solve(start+1,n,acc+"+");
        }
    }

}




class Scanner
{
    StringTokenizer st;
    BufferedReader br;

    public Scanner(InputStream s){	br = new BufferedReader(new InputStreamReader(s));}

    public String next() throws IOException
    {
        while (st == null || !st.hasMoreTokens())
            st = new StringTokenizer(br.readLine());
        return st.nextToken();
    }

    public int nextInt() throws IOException {return Integer.parseInt(next());}

    public long nextLong() throws IOException {return Long.parseLong(next());}

    public String nextLine() throws IOException {return br.readLine();}

    public double nextDouble() throws IOException
    {
        String x = next();
        StringBuilder sb = new StringBuilder("0");
        double res = 0, f = 1;
        boolean dec = false, neg = false;
        int start = 0;
        if(x.charAt(0) == '-')
        {
            neg = true;
            start++;
        }
        for(int i = start; i < x.length(); i++)
            if(x.charAt(i) == '.')
            {
                res = Long.parseLong(sb.toString());
                sb = new StringBuilder("0");
                dec = true;
            }
            else
            {
                sb.append(x.charAt(i));
                if(dec)
                    f *= 10;
            }
        res += Long.parseLong(sb.toString()) / f;
        return res * (neg?-1:1);
    }

    public boolean ready() throws IOException {return br.ready();}


}