Problem:
Score : 300 points

Problem Statement

Sitting in a station waiting room, Joisino is gazing at her train ticket.

The ticket is numbered with four digits A, B, C and D in this order, each between 0 and 9 (inclusive).

In the formula A op1 B op2 C op3 D = 7, replace each of the symbols op1, op2 and op3 with + or - so that the formula holds.

The given input guarantees that there is a solution. If there are multiple solutions, any of them will be accepted.

Constraints

0≤A,B,C,D≤9

All input values are integers.

It is guaranteed that there is a solution.

Input

Input is given from Standard Input in the following format:

ABCD

Output

Print the formula you made, including the part =7.

Use the signs + and -.

Do not print a space between a digit and a sign.

Sample Input 1

1222

Sample Output 1

1+2+2+2=7

This is the only valid solution.

Sample Input 2

0290

Sample Output 2

0-2+9+0=7

0 - 2 + 9 - 0 = 7 is also a valid solution.

Sample Input 3

3242

Sample Output 3

3+2+4-2=7

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String abcd = sc.next();
        int n = abcd.length() - 1;
        StringBuilder res = null;
        for (int bit = 0; bit < (1 << n); bit++) {
            res = new StringBuilder();
            res.append(abcd.charAt(0));
            int ans = 0;
            for (int i = 0; i < n; i++) {
                char num = abcd.charAt(i);
                if ((bit>> i & 1 ) == 1) {
                    res.append('+');
                    res.append(num);
                    ans += num - '0';
                } else {
                    res.append('-');
                    res.append(num);
                    ans -= num - '0';
                }
            }
            if (ans == 7) {
                break;
            }
        }
        System.out.println(res.toString() + "=7");
    }
}