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;
using System.Collections.Generic;

namespace C
{
    class Program
    {
        static void Main(string[] args)
        {
            var abcd = Console.ReadLine().ToCharArray().Select(x => int.Parse(x.ToString())).ToArray();
            var a = abcd[0];
            var b = abcd[1];
            var c = abcd[2];
            var d = abcd[3];

            string[] op = new String[2] { "+", "-" };
            string[] ansString = new String[8] { $"{a}", "+", $"{b}", "+", $"{c}", "+", $"{d}", "=7" };
            int ansA = a;

            bool notAnswered = true;

            for (int i = 0; i < 2 && notAnswered; i++)
            {
                int ansAB = ansA;
                ansString[1] = op[i];
                if (i == 0) ansAB +=b;
                else ansAB -= b;

                for (int j = 0; j < 2 && notAnswered; j++)
                {
                    int ansABC = ansAB;
                    ansString[3] = op[j];
                    if (j == 0) ansABC += c;
                    else ansABC -= c;

                    for (int k = 0; k < 2 && notAnswered; k++)
                    {
                        int ans = ansABC;
                        ansString[5] = op[k];
                        if (k == 0) ans += d;
                        else ans -= d;

                        if (ans == 7)
                        {
                            foreach (var x in ansString) Console.Write(x);
                            notAnswered = false;
                        }
                    }
                }
            }
        }
    }
}