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 Python (3.8.2) (judge verdict: Wrong Answer)

#引数としてopを追加
#opには計算で用いた演算子が文字列として格納されている
def func(i,x,op):
    #ベースケース
    if i == 4:
        if x == 7: return op
        else: return ""

    #足す場合
    opP = func(i+1, x + int(S[i]), op+"+")
    if opP != "": return opP

    #引く場合
    opM = func(i+1, x - int(S[i]), op+"-")
    if opM != "": return opM

    return ""