text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE table_name_18 (masculine_an_stems VARCHAR, feminine_ō_stems VARCHAR, masculine_u_stems VARCHAR)
  ### Question:
  What is the an-stem for the word which has an ö-stems of siangar and an u-stem ending of syni?
  ### Answer:
  SELECT masculine_an_stems FROM table_name_18 WHERE feminine_ō_stems = "siangar" AND masculine_u_stems = "syni"