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;


namespace AtC
{
    class Program
    {
        static void Main(string[] args)
        {
            var arr = ReadString().Select(val => val - '0').ToArray();
            for (int i = 0; i < 8; i++)
            {
                int sum = arr[0];
                for (int r = 0; r < 3; r++)
                {
                    sum += ((i >> r) & 1) == 0 ? arr[r + 1] : -arr[r + 1];
                }

                if (sum == 7)
                {
                    for (int r = 0; r < 3; r++)
                    {
                        Console.Write(arr[r]);
                        Console.Write(((i >> r) & 1) == 0 ? '+' : '-');
                    }

                    Console.Write(arr[3]);
                    Console.WriteLine("=7");
                    return;
                }
            }
        }

        //最小公倍数
        static int LCM(int num1, int num2)
        {
            var gcd = GCD(num1, num2);
            return num1 * (num2 / gcd);
        }

        static long LCM(long num1, long num2)
        {
            var gcd = GCD(num1, num2);
            return num1 * (num2 / gcd);
        }

        //最大公約数
        static int GCD(int num1, int num2)
        {
            int a = Math.Max(num1, num2);
            int b = Math.Min(num1, num2);
            int mod;
            while ((mod = a % b) != 0)
            {
                a = b;
                b = mod;
            }

            return b;
        }

        static long GCD(long num1, long num2)
        {
            long a = Math.Max(num1, num2);
            long b = Math.Min(num1, num2);
            long mod;
            while ((mod = a % b) != 0)
            {
                a = b;
                b = mod;
            }

            return b;
        }

        static int[] ReadIntArray()
        {
            return Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        }

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

        static long[] ReadLongArray()
        {
            return Console.ReadLine().Split(' ').Select(long.Parse).ToArray();
        }

        static long ReadLong()
        {
            return long.Parse(Console.ReadLine());
        }

        static string ReadString()
        {
            return Console.ReadLine();
        }

        static void Out(object o)
        {
            Console.WriteLine(o);
        }
    }

    static class EnumerableExtension
    {
        public delegate void Function<in T>(T val);

        public static void ForEach<T>(this IEnumerable<T> enumerable, Function<T> function)
        {
            foreach (var x in enumerable)
            {
                function(x);
            }
        }
    }

    class PriorityQueue<T>
    {
    }
}