Question: What was the delivery date when s2 (lst) type, s2 (frigate) type, c1-m type was delivered?
Schema: create table table_11552751_2 (ship_types_delivered varchar, PRIMARY KEY (ship_types_delivered))
SQL: select 1 as st_ship_delivery_date from table_11552751_2 where ship_types_delivered = "s2 (lst) type, s2 (frigate) type, c1-m type"