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(unused_imports)]

use text_io::*;
use std::collections::*;
use std::process::exit;
use std::cmp::*;
use itertools::Itertools;

fn main() {
    let mut a:String = read!();
    let vv:Vec<char> = a.chars().collect_vec();
    let mut v:Vec<isize> = Vec::new();
    for i in 0..vv.len() {
        if vv[i]=='0' {v.push(0) }
        if vv[i]=='1' {v.push(1) }
        if vv[i]=='2' {v.push(2) }
        if vv[i]=='3' {v.push(3) }
        if vv[i]=='4' {v.push(4) }
        if vv[i]=='5' {v.push(5) }
        if vv[i]=='6' {v.push(6) }
        if vv[i]=='7' {v.push(7) }
        if vv[i]=='8' {v.push(8) }
        if vv[i]=='9' {v.push(9) }
    }
    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]) }
    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]) }
}