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;
#if !DEBUG
    using System.IO;
#endif

public class Program {

    static int[] arr;
    static List<string> answers = new List<string>();
    static void Calculate(int p, bool isPlus, string history, int remainN) {
        if (p > 3) {
            if (remainN == 0) {
                answers.Add(history);
            }
            return;
        }

        if (p != 0) {
            history += isPlus ? "+" : "-";
        }

        history += arr[p].ToString();

        var nextRemainN = isPlus ? remainN - arr[p] : remainN + arr[p];

        Calculate(p + 1, true, history, nextRemainN);
        Calculate(p + 1, false, history, nextRemainN);
    }

    public static void Main() {
        #region SetAutoFlushIsFalse
#if !DEBUG
        var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
        Console.SetOut(sw);
#endif
        #endregion
        arr = Console.ReadLine().Select(i => int.Parse(i.ToString())).ToArray();
        Calculate(0, true, "", 7);
        var answer = answers.First();
        Console.WriteLine(answer + "=7");
        #region Flush
#if !DEBUG
        Console.Out.Flush();
        sw.Close();
#endif
        #endregion
    }
}


static class ReadLib {
    public static long ReadAsLong() {
        return long.Parse(Console.ReadLine());
    }

    public static int ReadAsInt() {
        return int.Parse(Console.ReadLine());
    }

    public static int[] ReadAsIntArray() {
        return Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
    }

    public static string[] ReadAsStringArray() {
        return Console.ReadLine().Split(' ');
    }

    public static int[] ReadNTimesAsInt(int n) {
        return Enumerable.Range(1, n).Select(s => int.Parse(Console.ReadLine())).ToArray();
    }
}