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;

namespace algorithm
{
	class Program
	{

		static void Main(string[] args)
		{

			int[] calc = { 0,0,0 };
			int[] c = Console.ReadLine().ToCharArray().Select(x => int.Parse(x.ToString())).ToArray();
			List<String> list = new List<string>();
			int ans = 0;
			for (int i = 0; i < 1 << calc.Length; i++)
			{
				ans = c[0];
				StringBuilder sb = new StringBuilder();
				for (int j = 0; j < calc.Length; j++)
				{
					sb.Append(c[j]);
					//iを右シフトして最下位ビットをチェック
					if ((i >> j & 1) == 1)
					{
						ans += c[j + 1];
						sb.Append("+");
					}else
					{
						ans -= c[j + 1];
						sb.Append("-");
					}
				}
				sb.Append(c[c.Length-1]);
				sb.Append("=7");
				if (ans == 7)
				{
					Console.WriteLine(sb.ToString());
					return;
				}

			}
			

		}


	}
}