This is the 10467th most frequent Polish word.
czystych
"Clean" or "pure" (genitive plural form of "czysty").
Here, 'czystych' functions as a plural adjective describing 'kartek,' which are 'clean.'
Mam stos czystych kartek na biurku.
I have a stack of clean sheets on the desk.
In this sentence, 'czystych' acts as a plural adjective describing 'relacjach,' implying 'pure' or 'honest.'
Musimy żyć w czystych relacjach z innymi.
We must live in pure relationships with others.
Here, 'czystych' again serves as a plural adjective modifying 'szklanek,' denoting they are 'clean.'