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 Ruby (2.3.3) (judge verdict: Accepted)

A, B, C, D = gets.split('').map &:to_i
plus_list = []
minus_list = []
ret = [A.to_s]
[0, 1].each do |b|
    if b == 0 
        ret << '-' << B.to_s 
        minus_list << B
    else
        ret << '+' << B.to_s 
        plus_list << B
    end
    [0, 1].each do |c|
        if c == 0 
            ret << '-' << C.to_s 
            minus_list << C
        else
            ret << '+' << C.to_s 
            plus_list << C
        end
        [0, 1].each do |d|
            if d == 0
                ret << '-' << D.to_s 
                minus_list << D
            else
                ret << '+' << D.to_s 
                plus_list << D
            end
            if A + plus_list.inject(0, :+) - minus_list.inject(0, :+) == 7
                puts ret.join + "=7"
                exit
            else
                ret.delete_at(-1)
                if ret[-1] == '-'
                    minus_list.delete_at(-1)
                else
                    plus_list.delete_at(-1)
                end
                ret.delete_at(-1)
            end
        end
        ret.delete_at(-1)
        if ret[-1] == '-'
            minus_list.delete_at(-1)
        else
            plus_list.delete_at(-1)
        end
        ret.delete_at(-1)
    end
    ret.delete_at(-1)
    if ret[-1] == '-'
        minus_list.delete_at(-1)
    else
        plus_list.delete_at(-1)
    end
    ret.delete_at(-1)
end
puts 'error!'