CREATE TABLE table_204_54 (id DECIMAL, "pondicherry assembly" TEXT, "duration" TEXT, "name of m.l.a." TEXT, "party affiliation" TEXT, "election year" DECIMAL)

who served after v. vaithilingam ?
SELECT "name of m.l.a." FROM table_204_54 WHERE "duration" > (SELECT "duration" FROM table_204_54 WHERE "name of m.l.a." = 'v. vaithilingam' ORDER BY "duration" DESC LIMIT 1) ORDER BY "duration" LIMIT 1
SELECT "name of m.l.a." FROM "table_204_54" WHERE "duration" > (SELECT "duration" FROM "table_204_54" WHERE "name of m.l.a." = 'v. vaithilingam' ORDER BY "duration" DESC NULLS LAST LIMIT 1) ORDER BY "duration" NULLS FIRST LIMIT 1