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 JavaScript (node.js v5.12) (judge verdict: Accepted)

function Main(input){
  var inputs = input.split("");
  var a = [];
  function Func(n,sum){
    if(n == 0){
      if(sum == 0){
        return true;}
    }else{
      if(Func(n-1,sum+new Number(inputs[n-1])) == true){
        a[n-1] = "-";
        return true;
      }else if(Func(n-1,sum-new Number(inputs[n-1])) == true){
        a[n-1] = "+";
        return true;
      }else{
        return false;
      }
    }
  }  
  if(Func(4,7) == true){
    console.log(inputs[0] + a[1] + inputs[1] + a[2] + inputs[2] + a[3] + inputs[3] + "=7" );
  }else{
    console.log("program error");
  }  
}
  Main(require('fs').readFileSync('/dev/stdin','utf8'));