CREATE TABLE table_17197 ("Unit" TEXT, "Commander" TEXT, "Complement" TEXT, "Killed" TEXT, "Wounded" TEXT, "Missing" TEXT)

Name the number of complement for 4th hanoverian brigade
SELECT COUNT("Complement") FROM table_17197 WHERE "Unit" = '4th Hanoverian Brigade'
SELECT COUNT("Complement") FROM "table_17197" WHERE "Unit" = '4th Hanoverian Brigade'