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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        Main m = new Main(sc);
        m.show(m.solve());
    }
    
    Scanner sc;
    String S;
    
    //入力
    Main(Scanner sc) {
        this.sc = sc;
        S = sc.next();
    }
    
    //解答処理
    String solve() {
        String[] s = S.split("");
        int A = Integer.parseInt(s[0]);
        int B = Integer.parseInt(s[1]);
        int C = Integer.parseInt(s[2]);
        int D = Integer.parseInt(s[3]);
        
        String op1 = null;
        String op2 = null;
        String op3 = null;
        
        if (A+B+C+D == 7){
            op1 = "+"; op2 = "+"; op3 = "+";
        } else if (A-B+C+D == 7){
            op1 = "-"; op2 = "+"; op3 = "+";
        } else if (A+B-C+D == 7){
            op1 = "+"; op2 = "-"; op3 = "+";
        } else if (A+B+C-D == 7){
            op1 = "+"; op2 = "+"; op3 = "-";
        } else if (A-B+C-D == 7){
            op1 = "-"; op2 = "+"; op3 = "-";
        } else if (A+B-C-D == 7){
            op1 = "+"; op2 = "-"; op3 = "-";
        } else if (A-B-C+D == 7){
            op1 = "-"; op2 = "-"; op3 = "+";
        } else if (A-B-C-D == 7){
            op1 = "-"; op2 = "-"; op3 = "-";
        }
        
        
        String f = A + op1 + B + op2 + C + op3 + D + "=7";
        return f;
    }
    
    //出力
    void show(String answer) {
        System.out.println(answer);
    }
}