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.Text;

namespace AtTest.BitAll
{
    class AtTemplate
    {
        static void Main(string[] args)
        {
            Method(args);
            Console.ReadLine();
        }

        static void Method(string[] args)
        {
            string input = Console.ReadLine();
            int a = input[0] - '0';
            int b = input[1] - '0';
            int c = input[2] - '0';
            int d = input[3] - '0';

            int result;
            string [] opr = new string[3];
            for (int i = 0; i < 2; i++)
            {
                for (int j = 0; j < 2; j++)
                {

                    for (int k = 0; k < 2; k++)
                    {
                        result = 0;
                        if (i == 0)
                        {
                            result = a + b;
                            opr[0] = "+";
                        }
                        else
                        {
                            result = a - b;
                            opr[0] = "-";
                        }
                        if (j == 0)
                        {
                            result += c;
                            opr[1] = "+";
                        }
                        else
                        {
                            result -= c;
                            opr[1] = "-";
                        }
                        if (k == 0)
                        {
                            result += d;
                            opr[2] = "+";
                        }
                        else
                        {
                            result -= d;
                            opr[2] = "-";
                        }
                        if (result == 7)
                        {
                            string resultStr = input.Insert(1, opr[0]);
                            resultStr = resultStr.Insert(3, opr[1]);
                            resultStr = resultStr.Insert(5, opr[2]);
                            resultStr += "=7";
                            Console.WriteLine(resultStr);
                            return;
                        }
                    }
                }
            }
        }
    }
}