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;
using System.Text;
using System.Threading.Tasks;

namespace AtCorder
{
    class Program
    {
        static void Main(string[] args)
        {

            // ABC079C
            var ABCD = Console.ReadLine().ToCharArray().Select(x => int.Parse(x.ToString())).ToArray();

            // ３ビット分の総当たりを実施したい
            for (int i = 0; i < (1 << 3); i++)
            {

                long calc = ABCD[0];
                string str = ABCD[0].ToString();
                for (int j = 0; j < 3; j++)
                {
                    if ((i & (1 << j)) != 0)
                    {
                        calc += ABCD[j + 1];
                        str += "+" + ABCD[j + 1].ToString();
                    }
                    else
                    {
                        calc -= ABCD[j + 1];
                        str += "-" + ABCD[j + 1].ToString();
                    }
                }

                if (calc == 7)
                {
                    Console.WriteLine(str + "=7");
                    return;
                }
            }






            Console.ReadKey();
        }



        #region MyRegion

        public static int ReadInt()
        {
            return int.Parse(Console.ReadLine());
        }

        /// <summary>
        /// 空白区切の数値を取得する
        /// </summary>
        /// <returns>The read split int.</returns>
        public static int[] ReadSplitInt()
        {
            return Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray();
        }

        /// <summary>
        /// 空白区切の数値を取得
        /// </summary>
        /// <returns>The read split long.</returns>
        public static long[] ReadSplitLong()
        {
            return Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray();
        }


        public static int[][] ReadSplitIntLines(int n)
        {
            return Enumerable.Range(0, n).Select(x => ReadSplitInt()).ToArray();
        }

        public static long[][] ReadSplitLongLines(int n)
        {
            return Enumerable.Range(0, n).Select(x => ReadSplitLong()).ToArray();
        }

        public static long[][] ReadSplitLongLines(long n)
        {
            var ret = new List<long[]>();
            for (long i = 0; i < n; i++)
            {
                ret.Add(ReadSplitLong().ToArray());
            }

            return ret.ToArray();
        }

        #endregion

    }
}