What's the service number of the Jammu Duronto train? 
CREATE TABLE table_23477312_1 (service INTEGER, train_name VARCHAR)
SELECT MAX(service) FROM table_23477312_1 WHERE train_name = "Jammu Duronto"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_23477312_1 (service INTEGER, train_name VARCHAR) Question: What's the service number of the Jammu Duronto train?  [/INST] SELECT MAX(service) FROM table_23477312_1 WHERE train_name = "Jammu Duronto" </s>