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;

macro_rules! read {
    ($t: ty) => {
        {
            let mut input = String::new();
            io::stdin().read_line(&mut input).expect("could not read input");
            input.trim().parse::<$t>().unwrap()
        };
    };
    ($($t: ty),*) => {
        {
            let mut input = String::new();
            io::stdin().read_line(&mut input).expect("could not read input");
            let mut iter = input.trim().split_whitespace();
            ($(iter.next().unwrap().parse::<$t>().unwrap()), *)
        };
    }
}
macro_rules! read_vec {
    ($t: ty) => {
        {
            let mut input = String::new();
            io::stdin().read_line(&mut input).expect("could not read input");
            let iter = input.trim().split_whitespace();
            iter.map(|x| x.parse::<$t>().unwrap()).collect::<Vec<$t>>()
        };
    }
}
fn main() {

    let s = read!(String);
    let ns= s.chars().map(|c| c.to_digit(10).unwrap() as i32).collect::<Vec<i32>>();

    for op1 in ['+', '-'].iter() {

        for op2 in ['+', '-'].iter() {

            for op3 in ['+', '-'].iter() {
                let mut out: i32 = 0;
                match op1 {
                    &'+' => out = ns[0] + ns[1],
                    _ => out = ns[0] - ns[1],
                };
                match op2 {
                    &'+' => out = out + ns[2],
                    _ => out = out - ns[2]
                };
                match op3 {
                    &'+' => out = out + ns[3],
                    _ => out = out - ns[3]
                };
                if out == 7 {
                    println!("{}{}{}{}{}{}{}=7", ns[0], op1, ns[1], op2, ns[2], op3, ns[3]);
                    return;
                }
            }
        }
    }



}