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.Linq;
using static System.Console;
using static System.Math;

namespace abc79_c
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = Console.ReadLine();
            var op = new string[3];

            for(int i=0; i<(1<<3); i++){
                int sum=int.Parse(str[0].ToString());
                for(int j=0; j<3; j++){
                    if((i>>j & 1) == 1){
                        sum += int.Parse(str[j+1].ToString());
                        op[j] = "+";
                    }else{
                        sum -= int.Parse(str[j+1].ToString());
                        op[j] = "-";
                    }
                }

                if(sum == 7){
                    WriteLine($"{str[0]}{op[0]}{str[1]}{op[1]}{str[2]}{op[2]}{str[3]}=7");
                    break;
                }
            }
        }
    }
}