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++ (GCC 5.4.1) (judge verdict: Runtime Error)

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

int main() {
    char ch, b[4];
    int a[4], s1= 0,s2 = 0, i, j, k, m;
    for (i = 0; i < 4; i++) {
        cin >> ch;
        a[i] = ch - '0';
        s1 += a[i];
    }
    if (s1 == 7) cout << a[0] << '+' << a[1] << '+' << a[2] << '+' << a[3] << "=7" << endl;
    else {
		s2 = a[0] - a[1] - a[2] - a[3];
        if (s2 == 7) cout << a[0] << '-' << a[1] << '-' << a[2] << '-' << a[3] << "=7" << endl;
		else {
			for (k = 0; k < 2; k++) {
				for (i = 1; i < 4; i++) {
					for (j = 1; j < 4; j++) {
						if (j == i) k == 0 ? b[j] = '+' : b[j] = '-';
						else k == 0 ? b[j] = '-' : b[j] = '+';
					}
					m = k == 0 ? s2 + 2 * a[i]: s1 - 2 * a[i];
					if (m == 7) { cout << a[0] << b[1] << a[1] << b[2] << a[2] << b[3] << a[3] << "=7" << endl; exit(1); }
				}
			}
		}   
    }
}