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)

// package app;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Scanner;
import java.util.StringJoiner;
import java.util.stream.Stream;

public class Main {

    public static void main(final String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);

        int[] a = new int[4];
        boolean [] ops = new boolean[3];
        for (int i = 0; i < 4; i++) {
            a[i] = System.in.read() - '0';
        }

        String[] op = new String[]{"+", "-"};

        String expression = "";
        for (int i = 0; i < Math.pow(2, 3); i++) {
            int sum = a[0];

            ops[0] = (i & 1) == 1;
            ops[1] = ((i >> 1) & 1) == 1;
            ops[2] = ((i >> 2) & 1) == 1;

            for (int j = 0; j < 3; j++) {
                sum = calc(sum, ops[j], a[j + 1]);
            }

            if (sum == 7){
                expression = Objects.toString(a[0]);
                for (int j = 0; j < ops.length; j++) {
                    expression += op[ops[j] ? 0 : 1] + Objects.toString(a[j + 1]);
                }
                expression += "=7";
                break;
            }
        }

        System.out.println(expression);
    }

    static int calc(int num1, boolean op, int num2){
        return op ? num1 + num2 : num1 - num2;
    }

}