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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
	// AtCoder Beginner Contest 079
	// https://atcoder.jp/contests/abc079/tasks
	public static void main(String[] args) {
		FastReader sc = new FastReader();
		String ticket = sc.next();
		int[] tickets = new int[ticket.length()];
		
		for (int i = 0; i < ticket.length(); i++) {
			tickets[i] = ticket.charAt(i) - '0';
		}
		findTicket(tickets, "" + tickets[0], 1, tickets[0]);
	}
	
	private static void findTicket(int[] nums, String s, int curr, int sum) {
		if (s.length() == 7) {
			if (sum == 7) {
				System.out.println(s + "=7");
				return;
			} 
		} else {
			if (curr < nums.length) {
				findTicket(nums, s + "+" + nums[curr], curr+1, sum + nums[curr]);
				findTicket(nums, s + "-" + nums[curr], curr+1, sum - nums[curr]);
			}
		}
		
	}
	
	
	static class FastReader { 
        BufferedReader br; 
        StringTokenizer st; 
  
        public FastReader() { 
            br = new BufferedReader(new InputStreamReader(System.in)); 
        } 
  
        String next() { 
            while (st == null || !st.hasMoreElements()) { 
                try { 
                    st = new StringTokenizer(br.readLine()); 
                } catch (IOException  e) { 
                    e.printStackTrace(); 
                } 
            } 
            return st.nextToken(); 
        } 
  
        int nextInt() { 
            return Integer.parseInt(next()); 
        } 
  
        long nextLong() { 
            return Long.parseLong(next()); 
        } 
  
        double nextDouble() { 
            return Double.parseDouble(next()); 
        } 
  
        String nextLine() { 
            String str = ""; 
            try{ 
                str = br.readLine(); 
            } catch (IOException e) { 
                e.printStackTrace(); 
            } 
            return str; 
        } 
    } 
}