CREATE TABLE table_204_354 (id DECIMAL, "opus" TEXT, "title" TEXT, "genre" TEXT, "sub\\u00addivisions" TEXT, "libretto" TEXT, "composition" TEXT, "premiere date" TEXT, "place ,  theatre" TEXT)

which composition spanned a longer period from beginning of composition to premiere - elektra , or intermezzo ?
SELECT "title" FROM table_204_354 WHERE "title" IN ('elektra', 'intermezzo') ORDER BY "premiere date" - "composition" DESC LIMIT 1
SELECT "title" FROM "table_204_354" WHERE "title" IN ('elektra', 'intermezzo') ORDER BY "premiere date" - "composition" DESC NULLS LAST LIMIT 1