What is the total number of acres at Sai Tso Wan, opening before 1978?
CREATE TABLE table_name_29 (acres VARCHAR, landfill VARCHAR, opened VARCHAR)
SELECT COUNT(acres) FROM table_name_29 WHERE landfill = "sai tso wan" AND opened < 1978
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_name_29 (acres VARCHAR, landfill VARCHAR, opened VARCHAR) Question: What is the total number of acres at Sai Tso Wan, opening before 1978? [/INST] SELECT COUNT(acres) FROM table_name_29 WHERE landfill = "sai tso wan" AND opened < 1978 </s>