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)

namespace AtCoder.ABC.C079
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Numerics;
    using System.IO;

    using AtCoder.ABC.IO;

    public class C079
    {
        public void Solve(Parser parser, Printer printer)
        {
            var abcd = parser.Scan().Select(ch => int.Parse(ch.ToString())).ToArray();

            var a = abcd[0];
            var b = abcd[1];
            var c = abcd[2];
            var d = abcd[3];

            var got = Solve(a,b,c,d);

            printer.Write($"{got}");
            printer.WriteLine();
            printer.Flush();
        }

        private string Solve(int a,int b, int c, int d)
        {
            var got = "=7";
            for (int i = 0; i < 2; i++)
            {
                for (int j = 0; j < 2; j++)
                {
                    for (int k = 0; k < 2; k++)
                    {
                        var ret = a;
                        ret = Operate(ret,b,i);
                        ret = Operate(ret,c,j);
                        ret = Operate(ret,d,k);

                        if (ret == 7)
                        {
                            return $"{a}{ToOperator(i)}{b}{ToOperator(j)}{c}{ToOperator(k)}{d}"+got;
                        }
                    }
                }
            }
            return got;
        }

        private int Operate(int x,int y, int op)
        {
            if(op == 0)
            {
                return x + y;
            }    
            return x -y ;
        }

        private string ToOperator(int op){
            if(op == 0)
            {
                return "+";
            }
            return "-";
        }
    }

    static class Program
    {
        static void Main(string[] args)
        {
            var i = new Parser(Console.OpenStandardInput());
            var o = new Printer(Console.OpenStandardOutput());
            new C079().Solve(i, o);
        }
    }
}
namespace AtCoder.ABC.IO
{
    #region IO

    using System;
    using System.IO;
    using System.Text;
    using System.Linq;
    using System.Collections.Generic;
    using System.Globalization;

    public class Parser
    {
        public Parser(Stream stream)
        {
            str = stream;
        }

        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof;

        public bool IsEndOfStream
        {
            get { return isEof; }
        }

        public IEnumerable<Parser> Take(int n)
        {
            return Enumerable.Range(1, n).Select(_ => this);
        }

        private byte read()
        {
            if (isEof) return 0;
            if (ptr < len) return buf[ptr++];
            ptr = 0;
            if ((len = str.Read(buf, 0, 1024)) > 0) return buf[ptr++];
            isEof = true;
            return 0;
        }

        public char Char()
        {
            byte b;
            do b = read(); while ((b < 33 || 126 < b) && !isEof);
            return (char)b;
        }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }

        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }

        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0;
            byte b;
            var ng = false;
            do b = read(); while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-')
            {
                ng = true;
                b = read();
            }
            for (; ; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                ret = ret * 10 + b - '0';
            }
        }

        public int Integer()
        {
            return (isEof) ? int.MinValue : (int)Long();
        }

        public double Double()
        {
            var s = Scan();
            return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN;
        }

        static T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n)
        {
            return enumerate(n, Char);
        }

        public string[] Scan(int n)
        {
            return enumerate(n, Scan);
        }

        public double[] Double(int n)
        {
            return enumerate(n, Double);
        }

        public int[] Integer(int n)
        {
            return enumerate(n, Integer);
        }

        public long[] Long(int n)
        {
            return enumerate(n, Long);
        }
    }

    public class Printer : StreamWriter
    {
        public override IFormatProvider FormatProvider
        {
            get { return CultureInfo.InvariantCulture; }
        }

        public Printer(Stream stream)
            : base(stream, new UTF8Encoding(false, true))
        {
        }

        public Printer(Stream stream, Encoding encoding)
            : base(stream, encoding)
        {
        }

        public void Write<T>(string format, T[] source)
        {
            base.Write(format, source.OfType<object>().ToArray());
        }

        public void WriteLine<T>(string format, T[] source)
        {
            base.WriteLine(format, source.OfType<object>().ToArray());
        }
    }

    #endregion

}