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: Wrong Answer)

import java.io.FileInputStream;
import java.io.InputStream;
import java.util.Scanner;

public class Main {
	static Scanner sc;

	public static void main(String[] args) throws Exception {
		//InputStream in = new FileInputStream("src/input.txt");
		InputStream in = System.in;

		sc = new Scanner(in);

		String N = sc.next();

		int a = N.charAt(0) - '0';
		int b = N.charAt(1) - '0';
		int c = N.charAt(2) - '0';
		int d = N.charAt(3) - '0';

		for(int i = 0; i < 16; i++){
			String bin = String.format("%4s",Integer.toBinaryString(i)).replaceAll(" ", "0");
			//System.out.println(bin);
			int aa = bin.charAt(0) - '0';
			int bb = bin.charAt(1) - '0';
			int cc = bin.charAt(2) - '0';
			int dd = bin.charAt(3) - '0';
			aa=check(aa);
			bb=check(bb);
			cc=check(cc);
			dd=check(dd);
			//System.out.println(a*aa+b*bb+c*cc+d*dd);
			if(a*aa+b*bb+c*cc+d*dd == 7){
				System.out.println(a + out(bb) + b + out(cc) + c + out(dd) + d + "=7");
				break;
			}
		}
	}
	static int check(int i){
		if(i == 0){
			return -1;
		}else{
			return 1;
		}
	}

	static String out(int i){
		if(i == -1){
			return "-";
		}else{
			return "+";
		}
	}

}