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: Wrong Answer)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func getNextLine(scanner *bufio.Reader) string {
	var buffer string
	for {
		line, isPrefix, _ := scanner.ReadLine()
		buffer += string(line)
		if isPrefix == false {
			break
		}
	}
	return buffer
}

func getIntList(scanner *bufio.Reader) []int {
	list := strings.Split(getNextLine(scanner), " ")
	l := len(list)
	result := make([]int, l)
	for i := 0; i < l; i++ {
		result[i], _ = strconv.Atoi(list[i])
	}
	return result
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := bufio.NewReader(fp)

	s := getNextLine(scanner)
	for op1 := -1; op1 <= 1; op1 += 2 {
		for op2 := -1; op2 <= 1; op2 += 2 {
			for op3 := -1; op3 <= 1; op3 += 2 {
				sum := int(s[0] - '0')
				sum += op1 * int(s[1]-'0')
				sum += op2 * int(s[2]-'0')
				sum += op3 * int(s[3]-'0')
				if sum == 7 {
					op := [3]rune{'+', '+', '+'}
					if op1 == -1 {
						op[0] = '-'
					}
					if op2 == -1 {
						op[1] = '-'
					}
					if op3 == -1 {
						op[2] = '-'
					}
					fmt.Printf("%c%c%c%c%c%c%c", s[0], op[0], s[1], op[1], s[2], op[2], s[3])
					return
				}
			}
		}
	}
}