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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
import java.io.*;

public class Main {
	static int[] num;
	public static void main(String[] args) {
		FastScanner sc = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);
		String s = sc.next();
		num = new int[4];
		for(int i = 0; i < 4; i++) {
			num[i] = Integer.valueOf(s.charAt(i) - 48);
			//out.println(num[i]);
		}
		for(;;) {
			if (num[0] + num[1] + num[2] + num[3] == 7) {
				out.println(num[0] + "+" + num[1] + "+"  + num[2] + "+" + num[3] + "=7");
				break;
		}
			if (num[0] + num[1] + num[2] - num[3] == 7) {
				out.println(num[0] + "+" + num[1] + "+"  + num[2] + "-" + num[3] + "=7");
				break;
		}		
			if (num[0] + num[1] - num[2] + num[3] == 7) {
				out.println(num[0] + "+" + num[1] + "-"  + num[2] + "+" + num[3] + "=7");
				break;
		}
			if (num[0] - num[1] + num[2] + num[3] == 7) {
				out.println(num[0] + "-" + num[1] + "+"  + num[2] + "+" + num[3] + "=7");
				break;
		}
			if (num[0] + num[1] - num[2] - num[3] == 7) {
				out.println(num[0] + "+" + num[1] + "-"  + num[2] + "-" + num[3] + "=7");
				break;
		}
			if (num[0] - num[1] - num[2] + num[3] == 7) {
				out.println(num[0] + "-" + num[1] + "-"  + num[2] + "+" + num[3] + "=7");
				break;
		}
			if (num[0] - num[1] + num[2] - num[3] == 7) {
				out.println(num[0] + "-" + num[1] + "+"  + num[2] + "-" + num[3] + "=7");
				break;
		}
			if (num[0] - num[1] - num[2] - num[3] == 7) {
				out.println(num[0] + "-" + num[1] + "-"  + num[2] + "-" + num[3] + "=7");
				break;
		}
		}
		out.close();
	}
	


static class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}
}