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::*;


fn main() {
    let mut strs = String::new();
    let stdin = stdin();
    let mut stdinlock = stdin.lock();
    stdinlock.read_line(&mut strs).unwrap();
    let nindex = strs.trim().as_bytes();
    let a = (nindex[0] - 48u8) as i32;
    let b = (nindex[1] - 48u8) as i32;
    let c = (nindex[2] - 48u8 )as i32;
    let d = (nindex[3] - 48u8) as i32;

   if (a + b + c + d) as i32 == 7i32 {
       println!("{}+{}+{}+{}=7", a, b, c, d);
   } else if  (a + b + c - d )as i32 == 7i32 {
       println!("{}+{}+{}-{}=7", a, b, c, d);
   } else if (a+b-c+d)as i32 == 7i32 {
       println!("{}+{}-{}+{}=7", a, b, c, d);
   } else if (a+b-c-d)as i32 == 7i32 {
       println!("{}+{}-{}-{}=7", a, b, c, d);
   } else if (a-b+c+d)as i32 == 7i32 {
       println!("{}-{}+{}+{}=7", a, b, c, d);
   } else if (a-b+c-d)as i32 == 7i32 {
       println!("{}-{}+{}-{}=7", a, b, c, d);
   } else if (a-b-c+d)as i32 == 7i32 {
       println!("{}-{}-{}+{}=7", a, b, c, d);
   } else {
       println!("{}-{}-{}-{}=7", a, b, c, d);
   }
}