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(){

    int N,A[4],B[4],C[4],i,j;
    cin >> N;

    A[0] = N / 1000;
    A[1] = (N - 1000 * A[0]) / 100;
    A[2] = (N - 1000 * A[0] - 100 * A[1]) /10;
    A[3] = N - 1000 * A[0] - 100 * A[1] - 10 * A[2];
    
    for(i = 0; i < 4; i++){
        B[i] = A[i];
    }
    sort(A,A+4);
    reverse(A,A+4);

    int c = A[0];
    
    for(i = 1; i < 4; i++){
        if (c + A[i] > 7) {
            A[i] = -1 * A[i];
        }
        c += A[i];
    }

    for(i = 0; i < 4; i++){
        for(j = 0; j < 4; j++){
            if(A[j] < 0){
                if(B[i] == -1*A[j]) {
                    C[i] = A[j];
                    break;
                }
            }else{
                if(B[i] == A[j]){
                    C[i] = A[j];
                    break;
                }
            }
        }
    }

    cout << C[0];
    for(i = 1; i < 4; i++){
        if(C[i] >= 0){
            cout << "+" << C[i];
        }else{
            cout << C[i];
        }
    }
    cout << "=" << 7 <<  endl;

    return 0;
}