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)

def s()
  gets().chomp
end
def i()
  gets.to_i
end
def li()
  gets.split.map(&:to_i)
end
def ili()
  n = gets.to_i
  as = gets.split.map(&:to_i)
  [n, as]
end

def calc(num, ope)
  first=num[0]
  3.times{|i|
    if ope[i] == "+"
      first += num[i+1]
    elsif ope[i] == "-"
      first -= num[i+1]
    end
  }
  first.to_i
end

num = s().split("").map(&:to_f)
ope = ["+", "-"]
2.times{|i|
  2.times{|j|
    2.times{|k|
      if calc(num, [ope[i], ope[j], ope[k]]) == 7
        res = num[0].to_i.to_s
        res += ope[i] + num[1].to_i.to_s
        res += ope[j] + num[2].to_i.to_s
        res += ope[k] + num[3].to_i.to_s
        puts res+"=7"
        exit
      end
    }
  }
}