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.*;

public class Main {
    static String[] s;
    static int[] a;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        a = new int[4];
        s = new String[4];
        s = sc.next().split("");

        for (int i = 0; i < s.length; i++) {
            a[i] = Integer.parseInt(s[i]);
        }
        //bit全探索 2**3
        for (int i = 0; i < (1 << 3); i++) {

            int tmp = a[0];
            for (int j = 0; j < 3; j++) {
                if ((1 & i >> j) == 1) {
                    tmp += a[j + 1];
                } else {
                    tmp -= a[j + 1];
                }
            }
            if (tmp == 7) {
                System.out.print(s[0]);
                for (int j = 0; j < 3; j++) {
                    if ((1 & i >> j) == 1) {
                        System.out.print("+");
                    } else {
                        System.out.print("-");
                    }
                    System.out.print(a[j + 1]);
                }
                System.out.println("=7");
                return;
            }
        }
    }
}