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 (2.7.1) (judge verdict: Accepted)

def f(x)
  if x==1
    return "-"
  else
    return "+"
  end
end
n = gets.strip.chars.map(&:to_i)
ary = []
[0, 1].repeated_permutation(3) do |bits|
  sum = n[0]
  for i in 0..2
    if bits[i] == 1
      sum -= n[i+1]
    else
      sum += n[i+1]
    end
  end
  if sum == 7
    ary << [n[0],f(bits[0]),n[1],f(bits[1]),n[2],f(bits[2]),n[3],"=",7].to_a
  end
end
print ary[0].join("")