About the Authors

Péter L. Erdős

Contributed equally to this work with: Péter L. Erdős, Sándor Z. Kiss, István Miklós, Lajos Soukup

erdos.peter@renyi.mta.hu

Current address: Reáltanoda u 13-5, Budapest, H-1053, Hungary

Affiliation Alfréd Rényi Institute of Mathematics, Hungarian Academy of Sciences, Budapest, Hungary

Sándor Z. Kiss

Contributed equally to this work with: Péter L. Erdős, Sándor Z. Kiss, István Miklós, Lajos Soukup

Affiliations Institute for Computer Science and Control, Hungarian Academy of Sciences, Budapest, Hungary, Department of Algebra, University of Technology and Economics, Budapest, Hungary

István Miklós

Contributed equally to this work with: Péter L. Erdős, Sándor Z. Kiss, István Miklós, Lajos Soukup

Affiliations Alfréd Rényi Institute of Mathematics, Hungarian Academy of Sciences, Budapest, Hungary, Institute for Computer Science and Control, Hungarian Academy of Sciences, Budapest, Hungary

Lajos Soukup

Contributed equally to this work with: Péter L. Erdős, Sándor Z. Kiss, István Miklós, Lajos Soukup

Affiliation Alfréd Rényi Institute of Mathematics, Hungarian Academy of Sciences, Budapest, Hungary

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Wrote the paper: PLE SZK IM LS.