The problem with your search is that without a town you will not be able to get too far finding your connection to a Gönczi and Hajdú. There are 699 Gönczis, 3751 Hajdús and 1962 Hajdus (note the letter ú and u)listed in the telephone book.
Some of them probably are related to you but to find the correct one you will need a lot more information.