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.Collections.Generic;
using System.Linq;

class Progaram
{
    static char[] Ops;
    static int[] L;

    static void dfs(int i, int sum, char[] ops)
    {
        if (i == 3 && sum == 7)
        {
            Ops = ops;
            return;
        }
        if (i == 3)
        {
            //Console.WriteLine(sum);
            return;
        }
        ops[i] = '+';
        dfs(i + 1, sum + L[i + 1], ops);
        if (Ops != null) return;
        ops[i] = '-';
        dfs(i + 1, sum - L[i + 1], ops);
        return;
    }

    static void Main(string[] args)
    {
        L = Console.ReadLine().ToCharArray().Select(x => int.Parse(x.ToString())).ToArray();
        var ops = new char[3];
        dfs(0, L[0], ops);
        /*if (Ops == null)
        {
            Console.WriteLine("Null");
            return;
        }*/
        var res = $"{L[0]}{Ops[0]}{L[1]}{Ops[1]}{L[2]}{Ops[2]}{L[3]}=7";
        Console.WriteLine(res);
    }
}