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.Text;
using System.Numerics;
using System.IO;

namespace SolutionCS
{
    class Program
    {
        static int Calc(int x, int y, int op)
        {
            if ( op == 0)
            {
                return x - y;
            }
            return x + y;
        }

        static void PrintOp(int op)
        {
            if (op == 0)
            {
                Console.Write("-");
                return;
            }

            Console.Write("+");
        }

        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            int[] v = new int[4];

            for (int i = 0; i < 4; i++)
            {
                v[i] = (int)(s[i] - '0');
            }

            for(int op = 0; op < 8; op++)
            {
                int tmp;
                tmp = Calc(v[0], v[1], op & 0x01);
                tmp = Calc(tmp, v[2], op & 0x02);
                tmp = Calc(tmp, v[3], op & 0x04);

                if (tmp == 7)
                {
                    Console.Write(v[0]);
                    PrintOp(op & 0x01);
                    Console.Write(v[1]);
                    PrintOp(op & 0x02);
                    Console.Write(v[2]);
                    PrintOp(op & 0x04);
                    Console.Write(v[3]);
                    Console.WriteLine("=7");

                    return;
                }
            }
        }
    }
}