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 <string>
#include <vector>

using namespace std;
int main(void)
{
    string S;
    cin >> S;
    int ans;
    int n = 3;
    int bit, i;
    vector<int> num(n + 1);
    for (i = 0; i <= n; i++) num[i] = S[i] - '0';
    for(bit = (1 << n) - 1; bit >= 0; bit--)
    {
        ans = num[0];
        for (i = 1; i <= n; i++) ans += (bit & (1 << (i - 1)) ? num[i] : -num[i]);
        if (ans == 7) break;
    }
    cout << num[0];
    for (i = 1; i <= n; i++) cout << (bit & (1 << (i - 1)) ? "+" : "-") << num[i];
    cout << "=7" << endl;
    return 0;
}