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)

#![allow(non_snake_case)]
#![allow(unused_imports)]
use proconio::input;
use std::collections::HashMap;
use std::collections::VecDeque;
use std::cmp::max;
use std::cmp::min;

fn to_str(sgn: i64) -> String {
    return (if sgn == 1 { "+" } else { "-" }).to_string();
}

fn main() {
    input! {
        ABCD: String,
    }

    let A: i64 = ABCD[0..1].parse().unwrap();
    let B: i64 = ABCD[1..2].parse().unwrap();
    let C: i64 = ABCD[2..3].parse().unwrap();
    let D: i64 = ABCD[3..4].parse().unwrap();

    let pm: Vec<i64> = vec![1, -1];

    for &sgn1 in pm.iter() {
        for &sgn2 in pm.iter() {
            for &sgn3 in pm.iter() {
                let ans = A + sgn1 * B + sgn2 * C + sgn3 * D;

                if ans == 7 {
                    println!(
                        "{}{}{}{}{}{}{}=7",
                        A,
                        to_str(sgn1),
                        B,
                        to_str(sgn2),
                        C,
                        to_str(sgn3),
                        D
                    );
                    return;
                }
            }
        }
    }

}