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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;

int main(){
    int n;
    cin >> n;
    vector<int> v(4);
    for (int i = 3; i >= 0; --i) {
        v[i] = n % 10;
        n /= 10;
    }

    for (int i = 0; i < (1<<3); ++i) {
        int tmp = v[0];
        for (int j = 0; j < 3; ++j) {
            if(i & (1<<j)){
                tmp += v[j+1];
            }
            else{
                tmp -= v[j+1];
            }
        }
        if(tmp == 7){
            cout << v[0];
            for (int j = 0; j < 3; ++j) {
                if(i & (1<<j)) cout << '+';
                else cout << '-';
                cout << v[j+1];
            }
            cout << "=7" << endl;
            return 0;
        }
    }
}