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)

use proconio::input;
#[allow(unused_imports)]
use proconio::marker::{Bytes, Chars};
#[allow(unused_imports)]
use std::cmp::{min, max};

fn main() {
	input! {
		cs: Chars,
	}

	let a = (cs[0] as u8) as isize - 48;
	let b = (cs[1] as u8) as isize - 48;
	let c = (cs[2] as u8) as isize - 48;
	let d = (cs[3] as u8) as isize - 48;

	//println!("{},{},{},{}", a, b, c, d);

	//+++
	if a+b+c+d == 7 {
		println!("{}+{}+{}+{}=7", a, b, c, d);
		return;
	}
	//++-
	if a+b+c-d == 7 {
		println!("{}+{}+{}-{}=7", a, b, c, d);
		return;
	}
	//+-+
	if a+b-c+d == 7 {
		println!("{}+{}-{}+{}=7", a, b, c, d);
		return;
	}
	//+--
	if a+b-c-d == 7 {
		println!("{}+{}-{}-{}=7", a, b, c, d);
		return;
	}
	//-++
	if a-b+c+d == 7 {
		println!("{}-{}+{}+{}=7", a, b, c, d);
		return;
	}
	//-+-
	if a-b+c-d == 7 {
		println!("{}-{}+{}-{}=7", a, b, c, d);
		return;
	}
	//--+
	if a-b-c+d == 7 {
		println!("{}-{}-{}+{}=7", a, b, c, d);
		return;
	}
	//---
	if a-b-c-d == 7 {
		println!("{}-{}-{}-{}=7", a, b, c, d);
		return;
	}
}