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 <string>
using namespace std;
string s;
string ans;
bool ok = false;
void DFS(int nw,int c){
  if(nw == 4 && c == 7){
    if(!ok)cout << ans << "=7" << endl;
    ok = true;
    return;
  }else if(nw == 4){
    return;
  }
  ans.push_back('+');
  ans.push_back(s[nw]);
  DFS(nw+1,c+s[nw]-'0');
  ans.pop_back();
  ans.pop_back();
  ans.push_back('-');
  ans.push_back(s[nw]);
  DFS(nw+1,c-(s[nw]-'0'));
  ans.pop_back();
  ans.pop_back();
}
int main(){
  cin>>s;
  ans.push_back(s[0]);
  DFS(1,s[0]-'0');
}