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_23477312_1 (service INTEGER, train_name VARCHAR)
### Question:
What's the service number of the Jammu Duronto train? 
### Answer:
SELECT MAX(service) FROM table_23477312_1 WHERE train_name = "Jammu Duronto"