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};

#[fastout]
fn main() {
    input!{
        tmp: String,
    }
    let st = tmp.chars().collect::<Vec<char>>();
    for i in 0..1 << 3 {
	let mut ret: i32 = st[0] as i32 - '0' as i32;
	let mut vec = Vec::new();
	for j in 0..3 {
	    if (1 << j) & i == 0 {
		ret += st[j+1] as i32 - '0' as i32;
		vec.push('+');
	    } else {
		ret -= st[j+1] as i32 - '0' as i32;
		vec.push('-');
	    }
	}
	if ret == 7 {
	    for i in 0..3 {
		print!("{}{}", st[i], vec[i]);
	    }
	    println!("{}=7", st[3]);
	    break;
	}
    }
		
		
}