Name the number of complement for 4th hanoverian brigade
CREATE TABLE "table1_11793221_4" (
  "unit" text,
  "commander" text,
  "complement" text,
  "killed" text,
  "wounded" text,
  "missing" text
);
SELECT COUNT("complement") FROM "table1_11793221_4" WHERE "unit"='4th Hanoverian Brigade';