Definition: You will be given a context, a subject and a relation. Your task is to generate a question based on the subject and relation. The generated question should include the given subject. Try to use a minimum number of words that are not present in either context, subject or relation while generating question.

Positive Example 1 -
Input: Context : Isaac Nicola Romero (1916 in Havana, Cuba -- 1997) was a prominent Cuban guitarist and one of the founders of the modern Cuban Guitar School. 
Subject : Isaac Nicola 
Relation : place of birth
Output: What was Isaac Nicola's city of birth?

Positive Example 2 -
Input: Context : Both Timur and Demir are popular male names in Turkey today. 
Subject : Timur 
Relation : noble title
Output: What was the title that Timur held?

Negative Example 1 -
Input: Context : The Boeing 601 (sometimes referred to as the BSS-601, and previously as the HS-601) is a communications satellite bus introduced in 1987 by Hughes Space and Communications Company. 
Subject : Boeing 601 
Relation : service entry
Output: What is Boeing 601?

Negative Example 2 -
Input: Context : In 1956 and 1957, the British and Commonwealth system of battle honours recognised participation in the Battle of Villers-Bocage by the award to 11 units of the battle honour Villers Bocage, for service in expanding the bridgehead from 8--15 June. 
Subject : Battle of Villers-Bocage 
Relation : point in time
Output: who recognised participation in the Battle of Villers-Bocage?

Now complete the following example -
Input: Context : Used by the U.S. Army, the U.S. Marine Corps, as well as many foreign militaries, the M47 Dragon was first fielded in January 1975 to U.S. Army soldiers stationed in mainland Europe. 
Subject : M47 Dragon 
Relation : service entry
Output: 


Output: What year did M47 Dragon come into use?