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 <vector>
#include <string>
#include <tuple>
#include <algorithm>
#include <numeric>
#include <climits>
#include <map>
#include <functional>
#include <cmath>
#include <cassert>

using namespace std;

int main()
{
    char a, b, c, d;
    cin >> a >> b >> c >> d;

    a -= '0'; b -= '0'; c -= '0'; d -= '0';
    for (int i = 0; i < 0b1000; i++) {
        int sum = a;
        if (0b100 & i) sum -= b; else sum += b;
        if (0b010 & i) sum -= c; else sum += c;
        if (0b001 & i) sum -= d; else sum += d;
        if (sum == 7) {
            cout << (int)a << ((0b100 & i)?"-":"+")
                 << (int)b << ((0b010 & i)?"-":"+")
                 << (int)c << ((0b001 & i)?"-":"+")
                 << (int)d << "=7\n";
            break;
        }
    }
    return 0;
}