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 Haskell (GHC 7.10.3) (judge verdict: Accepted)

import Data.Char
import Text.Printf

main :: IO ()
main = getLine >>= solve . fmap (\x -> ord x - ord '0')

solve :: [Int] -> IO () 
solve [a, b, c, d] = format $ head [(x, y, z) | (x, op1) <- [('+', (+)), ('-', (-))], (y, op2) <- [('+', (+)), ('-', (-))], (z, op3) <- [('+', (+)), ('-', (-))], (op3 (op2 (op1 a b) c) d) == 7]
    where
        format :: (Char, Char, Char) -> IO ()
        format (x, y, z) = printf "%d%c%d%c%d%c%d=7\n" a x b y c z d