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 PHP (5.6.30) (judge verdict: Accepted)

<?php
// 桁数が増えてもOK！$valueと$sumを任意で変更する
$value = fgets(STDIN);
// 計算後の値
$sum = 7;
// 桁数(なぜか入力に改行(?)があるのでtrimする)
$length = strlen(trim($value));
// +,-の数
$signCount = $length - 1;
// 左から順番に1桁ずつ配列に格納
$array = array();
for ($i = 0; $i < $length; $i ++) {
    $array[] = (int) substr($value, $i, 1);
}

// 全探索(記号種類2(+,-)を計算回数分べき乗する)
// 1ならプラス、0ならマイナス
for ($i = 0; $i < pow(2, $signCount); $i ++) {
    $result = $array[0];
    $resultStr = $array[0];
    // 桁の右から比較する
    for ($j = $signCount - 1; $j >= 0; $j --) {
        // 左シフトした値と比べる
        if (($i & (1 << $j)) === (1 << $j)) {
            $result += $array[$signCount - $j];
            $resultStr .= "+" . $array[$signCount - $j];
        } else {
            $result -= $array[$signCount - $j];
            $resultStr .= "-" . $array[$signCount - $j];
        }
    }
    if ($result === $sum) {
        echo $resultStr . "=" . $sum;
        exit(0);
    }
}