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>

std::string ans;
std::vector<int> a;

void dfs(int i,int sum,std::string s){
    if(i == 4){if(sum == 7 && s[0] != '-')ans = s;}
    else{
        dfs(i + 1, sum + a[i], s + "+" + std::to_string(a[i]));
        dfs(i + 1, sum - a[i], s + "-" + std::to_string(a[i]));
    }
}



int main()
{
    std::string s;
    std::cin >> s;
    a.resize(4);
    for(int i = 0; i < 4; i++)a[i] = s[i] - '0';
    dfs(0,0,"");
    ans.erase(ans.begin());
    std::cout << ans + "=7" << std::endl;
}