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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>) {
    val sc = java.util.Scanner(System.`in`)
    val list = sc.next().toCharArray().map(Char::toString).map(String::toInt).toMutableList()
    val f = list.removeAt(0)
    op(list, f, "$f")
}

fun op(list: List<Int>, v: Int, s: String): Boolean {
    if (list.isEmpty()) {
        return if (v == 7) {
            println("$s=7")
            true
        } else {
            false
        }
    }
    val n = list[0]
    val nextList = list.slice(1 until list.count()).toList()
    if (op(nextList, v + n, "$s+$n")) {
        return true
    }
    if (op(nextList, v - n, "$s-$n")) {
        return true
    }
    return false
}