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 (1.42.0) (judge verdict: Accepted)

use proconio::{input, fastout};
use proconio::marker::{Chars};
use proconio::marker::Usize1;
use std::cmp::*;

macro_rules! debug {
      ($($a:expr),*) => {
          eprintln!(concat!($(stringify!($a), " = {:?}, "),*), $($a),*);
    }
}

#[fastout]
fn main() {
    input!{
        abcd: Chars,
    }

    let a: i64 = abcd[0].to_digit(10).unwrap() as i64;
    let b: i64 = abcd[1].to_digit(10).unwrap() as i64;
    let c: i64 = abcd[2].to_digit(10).unwrap() as i64;
    let d: i64 = abcd[3].to_digit(10).unwrap() as i64;

    if a+b+c+d==7 {
        println!("{}+{}+{}+{}=7", a,b,c,d);
    } else if a-b+c+d==7 {
        println!("{}-{}+{}+{}=7", a,b,c,d);
    } else if a+b-c+d==7 {
        println!("{}+{}-{}+{}=7", a,b,c,d);
    } else if a+b+c-d==7 {
        println!("{}+{}+{}-{}=7", a,b,c,d);
    } else if a-b-c+d==7 {
        println!("{}-{}-{}+{}=7", a,b,c,d);
    } else if a+b-c-d==7 {
        println!("{}+{}-{}-{}=7", a,b,c,d);
    } else if a-b+c-d==7 {
        println!("{}-{}+{}-{}=7", a,b,c,d);
    } else if a-b-c-d==7 {
        println!("{}-{}-{}-{}=7", a,b,c,d);
    }

}