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: Wrong Answer)

#include <iostream>
#include <algorithm>

using namespace std;

char opr(bool){
  if(opr) return '+';
  else return '-';
}

int main(){
  int A,result, right_id;
  cin >> A;
  int elem[4] = {(int)(A/1000),(int)((A%1000)/100),(int)((A%100)/10),A%10};
  bool op[8][3] = {{false,false,false},
      {false,false,true},
      {false,true,false},
      {false,true,true},
      {true,false,false},
      {true,false,true},
      {true,true,false},
      {true,true,true},};
  /*
  for(int i = 0; i < 8; i++){
    if(i < 4) op[i][0] = false;
    else op[i][0] = true;
    if(i % 4 < 2) op[i][1] = false;
    else op[i][1] = true;
    if(i % 2 < 1) op[i][2] = false;
    else op[i][2] = true;
  }
*/
  for(int id = 0; id < 8; id++){
    result = elem[0];
    for(int i = 0; i < 3; i++){
      if(op[id][i]) result += elem[i+1];
      else result -= elem[i+1];
    }
    if(result == 7) {
      right_id = id;
      break;
    }
  }
  cout << elem[0];
  for(int i = 0; i < 3; i++){
    cout << opr(op[right_id][i]) << elem[i+1];
  }
  cout << "=7" << endl;

  return 0;
}