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: Wrong Answer)

using System;

namespace abc079_c
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            bool found = false;
            int n = int.Parse(s[0].ToString());
            for (int i = 0; i < 2 && !found; i++)
            {
                n += i == 0 ? int.Parse(s[1].ToString()) : -int.Parse(s[1].ToString());
                for (int j = 0; j < 2 && !found; j++)
                {
                    n += j == 0 ? int.Parse(s[2].ToString()) : -int.Parse(s[2].ToString());
                    for (int k = 0; k < 2 && !found; k++)
                    {
                        n += k == 0 ? int.Parse(s[3].ToString()) : -int.Parse(s[3].ToString());
                        if (n == 7)
                        {
                            found = true;
                            Console.Write(s[0]);
                            Console.Write(i == 0 ? '+' : '-');
                            Console.Write(s[1]);
                            Console.Write(j == 0 ? '+' : '-');
                            Console.Write(s[2]);
                            Console.Write(k == 0 ? '+' : '-');
                            Console.WriteLine(s[3] + "=7");
                        }
                        else
                        {
                            n = int.Parse(s[0].ToString());
                        }
                    }
                }
            }
        }
    }
}