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>
#include <iostream>
#include <vector>
#include <algorithm>
#include <iterator>
#include <stdio.h>
#include <string>
#include <stdlib.h>
#include <cstdlib>

using namespace std;
typedef long long ll;

bool calc(string s, int i, string ans, int sum, string &ans2){
  string plus;
  plus += '+';
  plus += s[i+1];
  string minus;
  minus += '-';
  minus += s[i+1];
  /*cout << plus + " " + minus + " " << i <<  " " + ans + " " << sum <<endl;*/

  if(i == 3){
    if(sum == 7){
      ans2 = ans;
      return true;
    }
    else{
      return false;
    }
  }

  //+
  if(calc(s, i+1, ans += plus , sum + (int)(s[i+1] - '0'), ans2)){
    return true;
  }
  ans.pop_back();
  ans.pop_back();
  //-
  if(calc(s, i+1, ans += minus, sum - (int)(s[i+1] - '0'), ans2)){
    return true;
  }
  return false;
}

string conv(string s, int i, string &ans, int sum){
  string ans2;
  if(calc(s, i, ans, sum, ans2)){
    return ans2 += "=7";
  }
}



int main(){
  string S;
  cin >> S;
  string ans;
  ans += S[0];
  char aaa = S[0];
  int sum;
  sum = (int)(aaa - '0');
  cout << conv(S, 0, ans, sum) <<endl;
}