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 Rust (1.15.1) (judge verdict: Accepted)

macro_rules! get_char {
    () => {
        {
            let mut line: String = String::new();
            std::io::stdin().read_line(&mut line).unwrap();
            line.trim().chars().collect::<Vec<_>>()
        }
    };
}

fn main() {
    let s = get_char!();

    for bit in 0..(1 << s.len() - 1) {
        let mut total = 0;
        let mut res = "".to_string();

        res.push(s[0]);
        total += s[0].to_digit(10).unwrap() as i32;

        for (i, c) in s.iter().skip(1).enumerate() {
            let x = c.to_digit(10).unwrap() as i32;
            if bit & (1 << i) != 0 {
                total += x;
                res.push('+');
            } else {
                total -= x;
                res.push('-');
            }
            res.push(*c);
        }
        if total == 7 {
            println!("{}=7", res);
            std::process::exit(0);
        }
    }
}