void produs(unsigned int n, int &p)
{
    int AP[10] = {0};

    p = 1;
    while(n != 0)
    {
        int c = n % 10;
        n = n / 10;
        if(c % 2 == 0 && AP[c] == 0)
            AP[c] = 1;
    }
    for(int i = 2; i <= 8; i = i + 2)
    {
        if(AP[i] == 1)
            p = p * i;
    }

    if(p == 1)
        p = -1;
}