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 <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <iomanip>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;

int main() {
  string S; cin >> S;
  for(int bit = 0; bit < (1<<3); bit++) {
    int tmp = S[0] - '0';
    for(int i = 0; i < 3; i++) {
      if(bit & (1<<i)) tmp += S[i+1] - '0';
      else tmp -= S[i+1] - '0';
    }
    if(tmp == 7) {
      cout << S[0];
      for(int i = 0; i < 3; i++) {
        if(bit & (1<<i)) cout << '+';
        else cout << '-';
        cout << S[i+1] - '0';
      }
      cout << "=7" << endl;
      return 0;
    }
  }
  return 0;
}