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;

namespace AtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var p = new Program();
            p.Solve();
        }

        void Solve()
        {
            var line = Console.ReadLine().ToCharArray();
            var numbers = line.Select(x => int.Parse(x.ToString())).ToArray();

            for (int i = 0; i < 8; i++)
            {
                var sum = numbers[0];
                for (int j = 1; j <= 3; j++)
                {
                    sum += plus[j - 1] ? numbers[j] : -numbers[j];
                }
                if (sum == 7)
                    break;
                IncreaseBit();
            }

            string ans = numbers[0].ToString();
            for (int i = 0; i < 3; i++)
            {
                ans += (plus[i] ? "+" : "-") + numbers[i + 1];
            }
            ans += "=7";
            Console.WriteLine(ans);
        }

        private bool[] plus = new bool[3];
        void IncreaseBit()
        {
            for (int i = plus.Length - 1; i >= 0; i--)
            {
                plus[i] = !plus[i];
                if (plus[i])
                    break;
            }
        }

    }

    class BitArray
    {
        bool[] bits = new bool[3];
        public BitArray(int num)
        {

        }
    }
}