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.util.*;

public class Main {
	public static void main(String args[]) {
		Scanner sc = new Scanner(System.in);
		String str = sc.nextLine();
		int num[] = new int[4];
		for(int i = 0; i < 4; i++) {
			num[i] = Integer.parseInt(str.substring(i, i + 1));
		}
		
		int ans_ary[] = new int[4];
		ans_ary[0] = num[0];
		
		for(int i = 0; i < Math.pow(2, 4); i++) {
			int ans = num[0];
			for(int j = 0; j < 4; j++) {
				if((1 & i >> j) == 1) {
					ans += num[j];
					ans_ary[j] = num[j];
				} else {
					ans -= num[j];
					ans_ary[j] = -num[j];
				}
			}
			if(ans == 7) {
				break;
			}
		}
		
		String ans_str = String.valueOf(ans_ary[0]);
		for(int i = 0; i < 3; i++) {
			if(ans_ary[i + 1] >= 0) {
				ans_str += "+" + String.valueOf(ans_ary[i + 1]);
			} else {
				ans_str += String.valueOf(ans_ary[i + 1]);
			}
		}
		
		System.out.println(ans_str + "=7");
	}
}