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 <bits/stdc++.h>

using namespace std;

int main(){
    int n,a[4];
    cin>>n;
    for(int i=3;i>=0;i--){
        a[i]=n%10;
        n/=10;
    }
    int b;
    for(b=0;b<8;b++){
        int ans=a[0];
        for(int i=0;i<3;i++){
            if(b>>i&1)ans+=a[i+1];
            else ans-=a[i+1];    
        }
        if(ans==7)break;
    }
    cout<<a[0]<<(b>>0&1?'+':'-');
    cout<<a[1]<<(b>>1&1?'+':'-');
    cout<<a[2]<<(b>>2&1?'+':'-');
    cout<<a[3]<<"=7"<<"\n";
    return 0;
}