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.Text;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using static System.Console;
using static System.Math;

namespace C_test_For_Atcorder
{
    public static class Extensions
    {
        public static string Reverse(this string sourse){
            char[] chrAry = sourse.ToCharArray();
            Array.Reverse(chrAry);
            return new string(chrAry);
        }
    }

    public class Program
    {
        public static void Main(string[] args)
        {
            new Program().Solve(new ConsoleInput(Console.In, ' '));
        }

        public void Solve(ConsoleInput cin)
        {
            var S = cin.Read;
            var ans = 7 - (int)char.GetNumericValue(S[0]);
            var BCD = new int[3];
			BCD[0] = (int)char.GetNumericValue(S[1]);
			BCD[1] = (int)char.GetNumericValue(S[2]);
			BCD[2] = (int)char.GetNumericValue(S[3]);
            var ans2 = 0;
            for (int i = 0; i < 1 << 3;i++){
                ans2 = ans;
                for (int j = 0; j < 3; j++)
                {
                    
                    if ((i & (1 << j)) != 0)
                    {
                        ans2 += BCD[j];
                    }
                    else
                    {
                        ans2 -= BCD[j];
                    }
                }
                if(ans2 == 0){
                    String ansStr = ""+S[0];
					for (int j = 0; j < 3; j++)
					{

						if ((i & (1 << j)) != 0)
						{
                            ansStr +=  "-"+S[j + 1];
						}
						else
						{
                            ansStr += "+" +S[j + 1];
						}
					}
                    Console.WriteLine(ansStr+"=7");
                    return;
                }
            }

        }
    }

    public class ConsoleInput
    {
        private readonly System.IO.TextReader _stream;
        private char _separator = ' ';
        private Queue inputStream;

        public ConsoleInput(System.IO.TextReader stream, char separator = ' ')
        {
            this._separator = separator;
            this._stream = stream;
            inputStream = new Queue();
        }
        public string Read
        {
            get
            {
                if (inputStream.Count != 0) return (string)inputStream.Dequeue();
                string[] tmp = _stream.ReadLine().Split(_separator);
                for (int i = 0; i < tmp.Length; ++i)
                    inputStream.Enqueue(tmp[i]);
                return (string)inputStream.Dequeue();
            }
        }
        public string ReadLine { get { return _stream.ReadLine(); } }
        public int ReadInt { get { return int.Parse(Read); } }
        public long ReadLong { get { return long.Parse(Read); } }
        public double ReadDouble { get { return double.Parse(Read); } }
        public string[] ReadStrArray(long N) { var ret = new string[N]; for (long i = 0; i < N; ++i) ret[i] = Read; return ret; }
        public int[] ReadIntArray(long N) { var ret = new int[N]; for (long i = 0; i < N; ++i) ret[i] = ReadInt; return ret; }
        public long[] ReadLongArray(long N) { var ret = new long[N]; for (long i = 0; i < N; ++i) ret[i] = ReadLong; return ret; }
    }

}