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 Scala (2.13.1) (judge verdict: Accepted)

object Main extends App {
  val s = io.StdIn.readLine
  val a = s(0).asDigit
  val b = s(1).asDigit
  val c = s(2).asDigit
  val d = s(3).asDigit

  val ope = Seq("+", "-")
  val results = for {
    ope1 <- ope
    ope2 <- ope
    ope3 <- ope
    if ((ope1, ope2, ope3) match {
      case ("+","+","+") => a+b+c+d
      case ("+","+","-") => a+b+c-d
      case ("+","-","+") => a+b-c+d
      case ("+","-","-") => a+b-c-d
      case ("-","+","+") => a-b+c+d
      case ("-","+","-") => a-b+c-d
      case ("-","-","+") => a-b-c+d
      case ("-","-","-") => a-b-c-d
    }) == 7
  } yield s"$a$ope1$b$ope2$c$ope3$d=7"

  println(results.head)
}