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;

public class MainClass
{
	public const long Giri = 1000000007;

	public static void Main(string[] args)
	{
		string abcd = Console.ReadLine();
		var nums = new int[4];
		for(int i = 0; i < abcd.Length; i++)
			nums[i] = (int)(abcd[i]-'0');
		
		var n = abcd.Length - 1;
		
		for(int bit = 0; bit < (1 << n);  bit++)
		{
			long wa = nums[0];
			StringBuilder sb = new StringBuilder();;
			sb.Append(nums[0]);
			for(int i = 0; i < n; i++)
			{
				if(((bit>>i)&1)==0)
				{
					wa += nums[i+1];
					sb.Append('+');
				}
				else
				{
					wa -= nums[i+1];
					sb.Append('-');
				}
				sb.Append(nums[i+1]);
				
			}
			if(wa == 7)
			{
				sb.Append("=7");
				Console.WriteLine(sb);
				return;
			}
		}

	}
	
	static long GCD(long a, long b)
	{
		var v = new[] { a, b };
		while (v[1] != 0) { v = new[] { v[1], v[0] % v[1] }; }
		return v[0];
	}
	public static string[] Input() { return Console.ReadLine().Split(' '); }
	public static int Clamp(int val, int max, int min = 0) { return Math.Min(max, Math.Max(min, val)); }
}

public static class Smarter
{
	public static int ToInt(this string str) { return int.Parse(str); }
	public static long ToLong(this string str) { return long.Parse(str); }
	public static int[] ToInt(this string[] str)
	{
		var r = new int[str.Length];
		for(int i = 0; i < str.Length; i++) r[i] = str[i].ToInt();
		return r;
	 }
}