CREATE TABLE table_18641 ("District" CLOB, "Incumbent" CLOB, "Party" CLOB, "First elected" FLOAT, "Result" CLOB, "Candidates" CLOB)

How many parties does william b. cravens represent?
SELECT COUNT("Party") FROM table_18641 WHERE "Incumbent" = 'William B. Cravens'
SELECT COUNT("Party") FROM "table_18641" WHERE "Incumbent" = 'William B. Cravens'