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 (a, b, c, d) = readLine()?.toCharArray()?.map{ it.toInt() - 48 } ?: return

    // a は正なので、b,c,dの計算結果を7-aにする必要がある
    val total = 7 - a

    // +,-の組み合わせは8通り
    for (i in 0 until 8) {
        val bAppliedOpe1 = if (i.and(0b0100) == 0b0100) b else -b
        val cAppliedOpe2 = if (i.and(0b0010) == 0b0010) c else -c
        val dAppliedOpe3 = if (i.and(0b0001) == 0b0001) d else -d

        if (bAppliedOpe1 + cAppliedOpe2 + dAppliedOpe3 == total) {
            val ope1 = if (i.and(0b0100) == 0b0100) '+' else '-'
            val ope2 = if (i.and(0b0010) == 0b0010) '+' else '-'
            val ope3 = if (i.and(0b0001) == 0b0001) '+' else '-'
            println("$a$ope1$b$ope2$c$ope3$d=7")
            return
        }
    }
}