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;

class Program
{
    static void Main()
    {
        var l = Console.ReadLine();
        for (int i = 0; i < 8; i++)
        {
            if (Calc(i, l))
            {
                Console.Write(l[0]);
                int cp = i;
                for (int j = 1; j <= 3; j++)
                {
                    if (cp % 2 == 0)
                    {
                        Console.Write('+');
                    }
                    else
                    {
                        Console.Write('-');
                    }
                    cp /= 2;
                    Console.Write(l[j]);
                }
                Console.Write("=7");
                Console.WriteLine();
                return;
            }
        }
    }

    static bool Calc(int n, string input)
    {
        int r = (input[0] - '0');
        for (int i = 1; i <= 3; i++)
        {
            if (n % 2 == 0)
            {
                r += input[i] - '0';
            }
            else
            {
                r -= input[i] - '0';
            }
            n /= 2;
        }
        return r == 7;
    }
}