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: Accepted)

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        String S;
        try (Scanner sc = new Scanner(System.in)) {
            S = sc.next();
        }
        char[] carr = S.toCharArray();
        int[] arr = new int[carr.length];
        for (int i = 0; i < carr.length; i++) {
            arr[i] = carr[i] - 48;
        }
        int baseMax = arr.length - 1;
        int bitSign = 0;
        while (bitSign < Math.pow(2, baseMax)) {
            StringBuilder sb = new StringBuilder();

            int result = arr[0];
            sb.append(arr[0]);

            for (int i = 0; i < baseMax; i++) {
                boolean isPlus = ((bitSign >>> (baseMax - 1 - i)) & 0x1) == 0;
                String s = isPlus ? "+" : "-";
                result += ((isPlus) ? (arr[i + 1]) : -(arr[i + 1]));
                sb.append(s).append(arr[i + 1]);
            }
            if (result == 7) {
                sb.append("=7");
                System.out.println(sb.toString());
                return;
            }
            bitSign++;
        }
    }
}