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;
using System.Threading.Tasks;

namespace C
{
    class Program
    {
        static IEnumerable<int> func(int a, int b)
        {
            yield return a + b;
            yield return a - b;
        }

        static void Main(string[] args)
        {
            var A = Console.ReadLine().Select(x => int.Parse(x + "")).ToArray();

            if (A[0] + A[1] + A[2] + A[3] == 7)
            {
                Console.WriteLine($"{A[0]}+{A[1]}+{A[2]}+{A[3]}=7");
            }
            else if (A[0] + A[1] + A[2] - A[3] == 7)
            {
                Console.WriteLine($"{A[0]}+{A[1]}+{A[2]}-{A[3]}=7");
            }
            else if (A[0] + A[1] - A[2] + A[3] == 7)
            {
                Console.WriteLine($"{A[0]}+{A[1]}-{A[2]}+{A[3]}=7");
            }
            else if (A[0] + A[1] - A[2] - A[3] == 7)
            {
                Console.WriteLine($"{A[0]}+{A[1]}-{A[2]}-{A[3]}=7");
            }
            else if (A[0] - A[1] + A[2] + A[3] == 7)
            {
                Console.WriteLine($"{A[0]}-{A[1]}+{A[2]}+{A[3]}=7");
            }
            else if (A[0] - A[1] + A[2] - A[3] == 7)
            {
                Console.WriteLine($"{A[0]}-{A[1]}+{A[2]}-{A[3]}=7");
            }
            else if (A[0] - A[1] - A[2] + A[3] == 7)
            {
                Console.WriteLine($"{A[0]}-{A[1]}-{A[2]}+{A[3]}=7");
            }
            else if (A[0] - A[1] - A[2] - A[3] == 7)
            {
                Console.WriteLine($"{A[0]}-{A[1]}-{A[2]}-{A[3]}=7");
            }
        }
    }
}