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)

use std::io::Read;

fn main() {
    let mut buf = String::new();
    std::io::stdin().read_to_string(&mut buf).unwrap();
    let mut iter = buf.split_whitespace();
    let mut n = vec![0;4];
    for (i,s) in iter.next().unwrap().chars().enumerate(){
        n[i] = (s as u8 - b'0') as i8;
    }
    'outer: for o1 in 0..2{
        let p1 = (o1 as i8)*2-1;
        for o2 in 0..2{
            let p2 = (o2 as i8)*2-1;
            for o3 in 0..2{
                let p3 = (o3 as i8)*2-1;
                if n[0]+n[1]*p1+n[2]*p2+n[3]*p3 == 7 {
                    println!("{}{}{}{}{}{}{}=7",n[0],
                            vec!["-","+"][o1],n[1],
                            vec!["-","+"][o2],n[2],
                            vec!["-","+"][o3],n[3]);
                    break 'outer
                }
            }
        }
    }
}