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;

int main() {
  int S;
  cin >> S;
  
  int A,B,C,D;
  A = (S / 1000) % 10;
  B = (S / 100) % 10;
  C = (S / 10) % 10;
  D = S % 10;
  
  
 
  if((A - B - C - D) == 7){
    cout << A << '-' << B << '-' << C << '-' << D << "=7" << endl;
  }else if((A - B - C + D) == 7){
	cout << A << '-' << B << '-' << C << '+' << D << "=7" << endl;
  }else if((A - B + C - D) == 7){
	cout << A << '-' << B << '+' << C << '-' << D << "=7" << endl;
  }else if((A - B + C + D) == 7){
	cout << A << '-' << B << '+' << C << '+' << D << "=7" << endl;
  }else if((A + B - C - D) == 7){
	cout << A << '+' << B << '-' << C << '-' << D << "=7" << endl;
  }else if((A + B - C + D) == 7){
	cout << A << '+' << B << '-' << C << '+' << D << "=7" << endl;
  }else if((A + B + C - D) == 7){
	cout << A << '+' << B << '+' << C << '-' << D << "=7" << endl;
  }else{
	cout << A << '+' << B << '+' << C << '+' << D << "=7" << endl;
  }

  return 0;
}