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>

bool once = false;

using namespace std;
void dfs(string S, int i){
    if (i == 3){
        int sum = S[0] - '0';
        if(S[1] == '+') sum += S[2] - '0';
        else sum -= S[2] - '0';
        if(S[3] == '+') sum += S[4] - '0';
        else sum -= S[4] - '0';
        if(S[5] == '+') sum += S[6] - '0';
        else sum -= S[6] - '0';
        //cout << "debug:" << S << endl;
        if(sum == 7 && once == false) {
            cout << S << "=7" << endl;
            once = true;
        }
    } else {
        string Splus = S;
        string Sminus = S;
        dfs(Splus.insert(2 * i + 1, "+"), i + 1);
        dfs(Sminus.insert(2 * i + 1, "-"), i + 1);
    }
}

int main() {
    string S;
    cin >> S;

    dfs(S, 0);
    return 0;
}