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::stdin;
use std::str::FromStr;
#[allow(dead_code, unused_mut)]
fn read<T: FromStr>() -> T {
    let mut s = String::new();
    stdin().read_line(&mut s).ok();
    s.trim().parse().ok().expect("1")
}
#[allow(dead_code, unused_mut)]
fn read_vec<T: FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().expect("2"))
        .collect()
}
#[allow(dead_code, unused_mut)]
fn read_two<T: FromStr>() -> (T, T) {
    let mut s = String::new();
    stdin().read_line(&mut s).unwrap();
    let mut x = s.split_whitespace().map(|x| x.parse().ok().unwrap());
    (x.next().unwrap(), x.next().unwrap())
}
#[allow(dead_code, unused_mut)]
fn read_three<T: FromStr>() -> (T, T, T) {
    let mut s = String::new();
    stdin().read_line(&mut s).unwrap();
    let mut x = s.split_whitespace().map(|x| x.parse().ok().unwrap());
    (x.next().unwrap(), x.next().unwrap(), x.next().unwrap())
}
#[allow(dead_code)]
fn remove_whitespace(s: &str) -> String {
    s.chars().filter(|c| !c.is_whitespace()).collect()
}
#[allow(unused_imports)]
use std::io::{stdout, Write};
fn main() {
    let strin: String = read();
    let v: Vec<u32> = strin.chars().map(|x| x.to_digit(10).unwrap()).collect();
    let v:Vec<i32> = v.into_iter().map(|x| x as i32).collect();
    if v[0] + v[1] + v[2] + v[3]  == 7 {
        println!("{}+{}+{}+{}=7", v[0], v[1], v[2], v[3]);
    } else if v[0] - v[1] + v[2] + v[3]  == 7 {
        println!("{}-{}+{}+{}=7", v[0], v[1], v[2], v[3]);
    } else if v[0] + v[1] - v[2] + v[3]  == 7 {
        println!("{}+{}-{}+{}=7", v[0], v[1], v[2], v[3]);
    } else if v[0] - v[1] - v[2] + v[3]  == 7 {
        println!("{}-{}-{}+{}=7", v[0], v[1], v[2], v[3]); //4
    } else if v[0] + v[1] + v[2] - v[3]  == 7 {
        println!("{}+{}+{}-{}=7", v[0], v[1], v[2], v[3]);
    } else if v[0] - v[1] + v[2] - v[3]  == 7 {
        println!("{}-{}+{}-{}=7", v[0], v[1], v[2], v[3]);
    } else if v[0] + v[1] - v[2] - v[3]  == 7 {
        println!("{}+{}-{}-{}=7", v[0], v[1], v[2], v[3]);
    } else if v[0] - v[1] - v[2] - v[3]  == 7 {
        println!("{}-{}-{}-{}=7", v[0], v[1], v[2], v[3]); //8
    }
}