How many number of paragraphs are there in chapter ID 18881?
number of paragraphs refers to ParagraphNum
SELECT COUNT(ParagraphNum) FROM paragraphs WHERE chapter_id = 18881
database name:db_id shakespeare
chapters table chapters Cols: id dtype integer, Act dtype integer, Scene dtype integer, Description dtype text, work id dtype integer, 
characters table characters Cols: id dtype integer, char name dtype text, abbreviation dtype text, Description dtype text, 
paragraphs table paragraphs Cols: id dtype integer, paragraph number dtype integer, Plain Text dtype text, character id dtype integer, chapter id dtype integer, 
works table works Cols: id dtype integer, Title dtype text, Long Title dtype text, character id dtype integer, genre type dtype text, 
