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 Common Lisp (SBCL 1.1.14) (judge verdict: Accepted)

(defun bit-collection (n function)
  (loop :for k :from 0 :upto (expt 2 n)
          :thereis(funcall function (loop :for j :from 0 :upto (1- n) :collect (logbitp j k)))))
(defun parse-int-char (n)
  (cond ((char= #\0 n) 0)
        ((<= 49 (char-code n) 57) (- (char-code n) 48))
        (t nil)))
(let* ((lst (mapcar #'parse-int-char (concatenate 'list (read-line)) )))
  (defun f (ll)
    (if (= 7 (reduce #'+ (cons (car lst) (mapcar (lambda (x y) (if x y (- 0 y))) ll (cdr lst)))))
        (progn (princ (car lst)) (mapcar (lambda (x y) (princ (if x "+" "-")) (princ y)) ll (cdr lst)) (princ "=7"))))
  (bit-collection 3 #'f))