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.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		// 入力1をnに入れる
		String s = sc.next();

		int n = s.length();

		for (int i = 0; i < 1 << n; i++) {
			StringBuilder sb = new StringBuilder(s);

			//ビット全探索で文字列Sに"+ - "を挿入していく
			for (int j = n - 2; j >= 0; j--) {
				if ((1 & i >> j) == 1) {
					sb.insert(j + 1, "+");
				} else {
					sb.insert(j + 1, "-");
				}
			}

			String str = sb.toString();
			int ans = Character.getNumericValue(str.charAt(0));
			//"+ - "入りの文字列をsplitして足し合わせる
			for (int j = 1; j < 2 * n - 2; j= j+2) {
				if (str.charAt(j) == '+') {
					ans += Character.getNumericValue(str.charAt(j+1));
				} else if (str.charAt(j) == '-') {
					ans -= Character.getNumericValue(str.charAt(j+1));
				}
			}

//			System.out.println("sb:" + sb);
//			System.out.println("ans:" + ans);
			if (ans == 7) {
				System.out.println(sb);
				break;
			}
		}
	}
}