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: Runtime Error)

#include <bits/stdc++.h>
#define rep(i, n) for (int i=0; i<(n); ++i)
using namespace std;

int hugou[3];

int dfs(vector<int> vec_s, int i){
    i += 1;
    // return 条件
    if (i > 3) {
        //cout << "i=3" << endl;
        int sum = 0;
        sum += vec_s[0];
        rep (j, 3) {
            if (hugou[j] == 0) {
                sum -= vec_s[j+1];
            } else {
                sum += vec_s[j+1];
            }
        }
        if (sum == 7) { 
            //rep(i, 4) cout << vec_s[i];
            char plmi[3];
            rep(j, 3) {
                if (hugou[j] == 0) {
                    plmi[j] = '-';
                } else {
                    plmi[j] = '+';
                }
            }
            rep(j, 3) {
                cout << vec_s[j] << plmi[j];
            }
            cout << vec_s[3] << "=7" << endl;
            exit(1);
        } else {
            return 0;
        }
    }
    // +をいれるとき
    hugou[i-1] = 1;
    dfs(vec_s, i);

    // -をいれるとき
    hugou[i-1] = 0;
    dfs(vec_s, i);

    return 0;
}

int main() {
    const int s_size=4;
    string s;
    cin >> s;
    vector<int> vec_s(s_size, 0);
    rep(i, s_size) {
        vec_s[i] = s[i] -'0';
    }
    // rep(i, 4) cout << vec_s[i];
    // cout << endl;
    dfs(vec_s, 0);
    return 0;
}