for catacondensed benzenoid graphs. Moreover, the closed formulas are used to characterize the graphs with the minimum and the maximum Wiener polarity index. Regarding the future work, it would be interesting to generalize the main result such that it could be used even for graphs sufficing weaker conditions. However, in such a case the formula would probably become much more complicated.

Acknowledgment {#acknowledgment .unnumbered}
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The author was financially supported by the Slovenian Research Agency (research core funding No. P1-0297 and J1-9109).

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