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;
using ll = long long;
using P = pair<int,int>;

int main(){
  string s;
  cin >> s;
  int n = s.size();
  string ans;
  for(int bit = 0; bit < (1<<(n-1)); bit++){
    int temp = s[0] - '0';
    ans = s[0];
    for(int i = 0; i < n-1; i++){
      if(bit & (1<<i)){
        temp += s[i+1] - '0';
        ans += "+";
        ans += s[i+1];
      }else{
        temp -= s[i+1] - '0';
        ans += "-";
        ans += s[i+1];
      }
    }
    if(temp == 7){
        cout << ans << "=7" << endl;
        return 0;
    }
  }
  return 0;
}