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 <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int a[10];
char s[10],c[10];

int main()
{
	scanf("%s",&s);
	for(int i=0;i<4;i++)
	{
		a[i]=s[i]-'0';
	}
	for(int i=1;i<=3;i++)
	{
		a[i]*=(-1);
		if(a[0]+a[1]+a[2]+a[3]==7)
		{
			for(int i=1;i<=3;i++)
			{
				if(a[i]<0) {c[i]='-';a[i]*=(-1);}
				else c[i]='+';
			}
			
			printf("%d%c%d%c%d%c%d=7",a[0],c[1],a[1],c[2],a[2],c[3],a[3]);
			return 0;
		}
	}
	for(int i=1;i<=3;i++)
	{
		a[i]*=(-1);
		if(a[0]+a[1]+a[2]+a[3]==7)
		{
			for(int i=1;i<=3;i++)
			{
				if(a[i]<0) {c[i]='-';a[i]*=(-1);}
				else c[i]='+';
			}
			
			printf("%d%c%d%c%d%c%d=7",a[0],c[1],a[1],c[2],a[2],c[3],a[3]);
			return 0;
		}
	}
	a[2]*=(-1);
	if(a[0]+a[1]+a[2]+a[3]==7)
	{
		for(int i=1;i<=3;i++)
		{
			if(a[i]<0) {c[i]='-';a[i]*=(-1);}
			else c[i]='+';
		}
		printf("%d%c%d%c%d%c%d=7",a[0],c[1],a[1],c[2],a[2],c[3],a[3]);
	}
	for(int i=1;i<=3;i++)
	{
		a[i]*=(-1);
		if(a[0]+a[1]+a[2]+a[3]==7)
		{
			for(int i=1;i<=3;i++)
			{
				if(a[i]<0) {c[i]='-';a[i]*=(-1);}
				else c[i]='+';
			}
			
			printf("%d%c%d%c%d%c%d=7",a[0],c[1],a[1],c[2],a[2],c[3],a[3]);
			return 0;
		}
	}
	return 0;
}