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.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    String[] c = str.split("");
    String[] op = new String[4];
    op[3] = "=";
    int[] num = new int[4];
    int result = 0;
    StringBuilder answer = new StringBuilder();
    for(int i = 0; i < 4; i++) {
      num[i] = Integer.parseInt(c[i]);
    }
    outside: for(int i = 0; i < 2; i++) {
      for(int j = 0; j < 2; j++) {
        for(int k = 0 ; k < 2; k++) {
          if(i == 0) {
            op[0] = "+";
            result += (num[0] + num[1]);
          } else {
            op[0] = "-";
            result += (num[0] - num[1]);
          }
          if(j == 0) {
            op[1] = "+";
            result += num[2];
          } else {
            op[1] = "-";
            result -= num[2];
          }
          if(k == 0) {
            op[2] = "+";
            result += num[3];
          } else {
            op[2] = "-";
            result -= num[3];
          }
          if(result == 7) {
            for(int l = 0; l < 4; l++) {
              answer.append(Integer.toString(num[l]));
              answer.append(op[l]);
            }
            answer.append("7");
            System.out.println(answer);
            break outside;
          } else {
            result = 0;
          }
        }
      }
    }
  }
}