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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (int)n; i++)
typedef long long ll;
typedef pair<int, int> p;

int main(){
  string s;
  cin >> s;
  vector<string>ans(9);
  ans[0]=s[0];
  for(int bit=0;bit<(1<<3);bit++){
    //cout<<bit<<endl;
    int sum=s[0]-'0';
    for(int i =0; i<3;i++){
      //cout<<i<<"aaa"<<endl;
      if(bit&(1<<i)){
        sum+=s[i+1]-'0'; 
        ans[2*(i+1)]=s[i+1];
        ans[2*i+1]='+';
      }
      else{
        sum-=s[i+1]-'0';
        ans[2*(i+1)]=s[i+1];
        ans[2*i+1]='-';
      }
    }

    if(sum==7){
      ans[7]='=';
      ans[8]='7';
      break;
    }
    
  }
  rep(i,9)cout<<ans[i];
  }