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) {
        Scanner scanner = new Scanner(System.in);
        int[] input = Arrays.stream(scanner.nextLine().split("")).mapToInt(Integer::parseInt).toArray();

        int opLength = input.length - 1;
        int opEnd = opLength - 1;

        for (int bit = 0; bit < (1<<opLength); bit++) {
            StringBuffer sb = new StringBuffer(2 *input.length - 1);
            sb.append(input[0]);
            long sum = input[0];

            for (int i = 0; i < opLength ; i++) {
                if ((bit & (1<<(opLength - 1 - i))) > 0) {
                    sum += input[i + 1];
                    sb.append("+");
                    sb.append(input[i + 1]);
                } else {
                    sum -= input[i + 1];
                    sb.append("-");
                    sb.append(input[i + 1]);
                }
            }

            if (sum == 7) {
                sb.append("=7");
                System.out.println(sb.toString());
                break;
            }
        }
    }
}