Name the slope length for gondola
CREATE TABLE "skilift_system" (
  "name_or_route" text,
  "type" text,
  "elevation_groundstation" real,
  "elevation_mountainstation" real,
  "slope_length" real,
  "capacity_in_persons_hour" real,
  "construction_year_s" text
);
SELECT MIN("slope_length") FROM "skilift_system" WHERE "type"='gondola';