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 <bits/stdc++.h>
#include<string>
#include<algorithm>
#include<stdio.h>
using ll = long long;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
static const int INFTY = (1<<21);
int nums[4],flag=0;
string str;





void search(int index, ll sum,string fomula){
    if(index ==3 && sum ==7){
        fomula += "=7";
        cout << fomula<< endl;
        flag++;
        return;
    }
    if(index <4 && flag ==0){
    search(index + 1, sum + nums[index+1],fomula + "+" + str[index+1]);
    }
    if(index <4 && flag ==0){
    search(index + 1, sum - nums[index+1],fomula + "-" + str[index+1]);
    }
}






int main(){
    cin >> str;
    rep(i,4) nums[i]=(int)(str[i]-'0');
    string ini{str[0]};
    search(0,nums[0],ini);
    return 0;

}