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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;

int main()
{
	int a[4], i, j, x, y, b[3], ans;
	string s;
	memset(b, 0, sizeof(b));

	cin >> s;

	for(i=0; i<4; i+=1)
	{
		string s1;
		s1+=s[i];
		a[i]=stoi(s1);
	}

	for(i=0; i<8; i+=1)
	{
		y=0;
		x=i;
		while(x>0)
		{
			b[y]=x%2;
			y+=1;
			x/=2;
		}

		ans=a[0];
		for(j=0; j<3; j+=1)
		{
			if(b[j]==1)
				ans+=a[j+1];
			else
				ans-=a[j+1];
		}
		if(ans==7)
			break;
	}

	for(i=0; i<=3; i+=1)
	{
		cout << a[i];
		if(i<3)
		{
			if(b[i]==1)
				cout << '+';
			else
				cout << '-';
		}
		else
			cout << "=7" << endl;
	}
}