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)

fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let v: Vec<isize> = s.trim().chars().map(|x| x.to_string().parse().unwrap()).collect();

    for o in 0..2_usize.pow(4) {
        let mut i = 0;
        let x = v.iter().fold(0, |a, b| if i==0||o&(1<<i)!=0 {i+=1; a+b} else {i+=1; a-b});
        if x==7 {
            print!("{}", v[0]);
            for i in 1..v.len() {
                print!("{}{}", if o&(1<<i)!=0 {"+"} else {"-"}, v[i]);
            }
            println!("=7");
            return;
        }

    }

}