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).ok();
    let mut v : Vec<i32> = Vec::new();
    for i in 0..4 {
        v.push(s.chars().nth(i).unwrap().to_digit(10).unwrap_or(0) as i32);
    }
    let mut end = false;
    for f1 in 0..2 {
        for f2 in 0..2 {
            for f3 in 0..2 {
                let mut ans = v[0];
                if f1 == 0 {
                    ans += v[1];
                }
                else {
                    ans -= v[1];
                }
                if f2 == 0 {
                    ans += v[2];
                }
                else {
                    ans -= v[2];
                }
                if f3 == 0 {
                    ans += v[3];
                }
                else {
                    ans -= v[3];
                }
                if ans == 7 {
                    println!("{}{}{}{}{}{}{}=7", v[0], if f1==0 {'+'} else {'-'}, v[1], if f2==0 {"+"} else {"-"}, v[2], if f3==0 {"+"}  else {"-"}, v[3]);
                    end = true;
                    break;
                }
            }
            if end {
                break;
            }
        }
        if end {
            break;
        }
    }
}