user: Question: When did the party elected in Jun. 1959 enter office?
Columns: ['Entered office', 'Left office', 'Party', 'Election', 'Coalition']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['4 January 1917', '25 February 1920', 'Home Rule Party', '1916', 'HP—OIP— PP']
SQL:

assistant: SELECT "Entered office" FROM "Table" WHERE "Election" = 'Jun. 1959';