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 (2.11.7) (judge verdict: Accepted)

import java.util.Scanner

import scala.collection.Searching._
import scala.annotation.tailrec
import scala.collection.immutable.Queue

class IUnionFind(val size: Int) {

  private case class Node(var parent: Option[Int], var treeSize: Int)

  private val nodes = Array.fill[Node](size)(new Node(None, 1))

  def union(t1: Int, t2: Int): IUnionFind = {
    if (t1 == t2) return this

    val root1 = root(t1)
    val root2 = root(t2)
    if (root1 == root2) return this

    val node1 = nodes(root1)
    val node2 = nodes(root2)

    if (node1.treeSize < node2.treeSize) {
      node1.parent = Some(t2)
      node2.treeSize += node1.treeSize
    } else {
      node2.parent = Some(t1)
      node1.treeSize += node2.treeSize
    }
    this
  }

  def connected(t1: Int, t2: Int): Boolean = t1 == t2 || root(t1) == root(t2)

  @tailrec
  private def root(t: Int): Int = nodes(t).parent match {
    case None => t
    case Some(p) => root(p)
  }
}


object Main {
  def solve(sc: => Scanner): Unit = {
    val N = sc.nextInt
    val A = N / 1000
    val B = N / 100 % 10
    val C = N / 10 % 10
    val D = N % 10
    if (A + B + C + D == 7) {
      printf("%d+%d+%d+%d=7", A, B, C, D)
    } else if (A + B + C - D == 7) {
      printf("%d+%d+%d-%d=7", A, B, C, D)
    } else if (A + B - C + D == 7) {
      printf("%d+%d-%d+%d=7", A, B, C, D)
    } else if (A + B - C - D == 7) {
      printf("%d+%d-%d-%d=7", A, B, C, D)
    } else if (A - B + C + D == 7) {
      printf("%d-%d+%d+%d=7", A, B, C, D)
    } else if (A - B + C - D == 7) {
      printf("%d-%d+%d-%d=7", A, B, C, D)
    } else if (A - B - C + D == 7) {
      printf("%d-%d-%d+%d=7", A, B, C, D)
    } else if (A - B - C - D == 7) {
      printf("%d-%d-%d-%d=7", A, B, C, D)
    }
  }

  def main(args: Array[String]): Unit = {
    val sc: Scanner = new Scanner(System.in)
    solve(sc)
  }
}