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 Go (1.6) (judge verdict: Accepted)

package main

import "fmt"

const (
	plus = iota
	minus
)

func main() {
	var abcd string
	fmt.Scan(&abcd)

	a := int(rune(abcd[0]) - '0')
	b := int(rune(abcd[1]) - '0')
	c := int(rune(abcd[2]) - '0')
	d := int(rune(abcd[3]) - '0')

	for i := 0; i < 2; i++ {
		for j := 0; j < 2; j++ {
			for k := 0; k < 2; k++ {
				if calc(calc(calc(a, b, i), c, j), d, k) == 7 {
					fmt.Println(format(a, b, c, d, i, j, k))
					return
				}
			}
		}
	}
}

func calc(a, b int, ope int) int {
	if ope == plus {
		return a + b
	} else {
		return a - b
	}
}

func opeStr(ope int) string {
	if ope == plus {
		return "+"
	} else {
		return "-"
	}
}

func format(a, b, c, d int, opeA, opeB, opeC int) string {
	return fmt.Sprintf("%d%s%d%s%d%s%d=7", a, opeStr(opeA), b, opeStr(opeB), c, opeStr(opeC), d)
}