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 <bits/stdc++.h>
using namespace std;
int main(){
vector<char>B(4);
for(int i=0;i<4;i++){
  cin>>B.at(i);
}
vector<int>A(4);
for(int i=0;i<4;i++){
  char m=B.at(i);
  int n=(unsigned char)m;
  A.push_back(n);
  
}
int sum=0;
vector<char>t(4);
for(int tmp=0;tmp<(1<<5);tmp++){
  bitset<4>s(tmp);
  for(int i=0;i<4;i++){
    if(s.test(i)){//trueの時+
     sum +=A.at(i);
     t.push_back('+');
     }else{
       sum-=A.at(i);
       t.push_back('-');
    }
  }
  if(sum==7){cout<<A.at(0)<<t.at(0)<<A.at(1)<<t.at(1)<<A.at(2)<<t.at(2)<<A.at(3)<<'='<<7<<endl;};
  return 0;
}
}