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: Wrong Answer)

fn main() {
  let mut buf = String::new();
  std::io::stdin().read_line(&mut buf).ok();
  let mut s: Vec<char> = buf.trim().chars().collect();
  
  let mut a: i32 = s[0] as i32;
  a = a - 48;
  let mut b: i32 = s[1] as i32;
  b = b - 48;
  let mut c: i32 = s[2] as i32;
  c = c - 48;
  let mut d: i32 = s[3] as i32;
  d = d - 48;
 
  if a + b + c + d == 7 {
    println!("{}+{}+{}+{}=7",a,b,c,d);
  }else if a+b+c-d == 7{
    println!("{}+{}+{}-{}=7",a,b,c,d);
  }else if a+b-c-d == 7{
    println!("{}+{}-{}-{}=7",a,b,c,d);
  }else if a-b-c-d == 7{
    println!("{}-{}-{}-{}=7",a,b,c,d);
  }else if a+b-c+d == 7{
    println!("{}+{}-{}+{}=7",a,b,c,d);
  }else if a-b-c+d == 7{
    println!("{}-{}-{}+{}=7",a,b,c,d);
  }else if a-b+c+d == 7{
    println!("{}-{}+{}-{}=7",a,b,c,d);
  }else if a-b+c-d == 7{
    println!("{}-{}+{}-{}=7",a,b,c,d);
  }
}