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;

class Program
{
    static void Main(string[] args)
    {
        List<int> abcd = Console.ReadLine().ToCharArray().Select((c) => int.Parse(c.ToString())).ToList();

        for(byte i = 0; i < 8; i++) //000~111
        {
            bool[] pm =
            {
                ((i & 1) == 1),
                ((i & 2) == 2),
                ((i & 4) == 4),
            };
            int culc = abcd[0] + (pm[0] ? 1 : -1) * abcd[1] + (pm[1] ? 1 : -1) * abcd[2] + (pm[2] ? 1 : -1) * abcd[3];
            if(culc == 7)
            {
                string ans = "";
                for(int j = 0; j < 4; j++)
                {
                    ans += abcd[j];
                    if (j < 3) ans += (pm[j]) ? "+" : "-";
                }
                ans += "=7";
                Console.WriteLine(ans);
                return;
            }
        }
    }
}