CREATE TABLE table_203_777 (id DECIMAL, "years" TEXT, "building" TEXT, "city" TEXT, "height  ( ctbuh ) " TEXT, "floors" DECIMAL)

how many floors are there in the tallest building in canada ?
SELECT "floors" FROM table_203_777 WHERE "years" = present_ref
SELECT "floors" FROM "table_203_777" WHERE "present_ref" = "years"