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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
public class Hello{
    public static void Main(){
        // Your code here!
        int[] a = Console.ReadLine().ToCharArray().Select(x => int.Parse(x.ToString())).ToArray();
        int n = a.Length - 1;
        
        
        for(int i = 0; i < Math.Pow(2, n); i++)
        {
            string[] s = new string[3];
            for(int j = 0; j < n; j++)
            {
                if((1 & i>>j) == 1) s[j] = "+";
                else s[j] = "-";
            }
            
            int sum = a[0];
            for(int k = 0; k < s.Length; k++)//7になるかどうか調べる
            {
                if(s[k] == "+") sum += a[k + 1];
                else sum -= a[k + 1];
            }
            
            if(sum == 7)
            {
                Console.WriteLine(a[0] + s[0] + a[1] + s[1] + a[2] + s[2] + a[3] + "=7");
                return;
            }
        }
        
    }
}