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 <iostream>
#include <cstdlib>
#include <string>

int main()
{
    bool operetors[3] = {true, true, true};
    int nums;
    int num[4];
    int i = 0;
    int j = 0;
    int sum = 0;
    char c[3];
    
    std::cin >> nums;
    num[3] = nums % 10;
    nums = nums / 10;
    num[2] = nums % 10;
    nums = nums / 10;
    num[1] = nums % 10;
    nums = nums / 10;
    num[0] = nums % 10;
    
    for(i = 0; i < 8; i++){
        sum = num[0];
        j = 1;
        operetors[0] = (i >> 2) & 1;
        operetors[1] = (i >> 1) & 1;
        operetors[2] = i & 1;
        
        while(j < 4){
            if(operetors[j - 1]){
                sum += num[j];
            }else{
                sum += (num[j] * -1);
            }
            j++;
        }
        if(sum == 7){
            break;
        }
    }
    j = 0;
    while(j < 3){
            if(operetors[j]){
                c[j] = '+';
            }else{
                c[j] = '-';
            }
        j++;
    }
    std::cout << num[0] << c[0] << num[1] << c[1] << num[2] << c[2] << num[3];
    return 0;
}