double avg(int first,...) {
    cout << "do we segfault here?";
    int count = 0, sum= 0, i= first;
    cout << "do we segfault here 2?";
    va_list marker;
    cout << "do we segfault here 3?";
    va_start(marker, first);
    while ( i != -1) {
        sum+=i;
        count++;
        i=va_arg(marker, int);
    }
    va_end(marker);
    return ( sum ? (sum/count) : 0 );
}