user: Question: How many different second members were there when John Rudhale was first member?
Columns: ['Elected', 'Assembled', 'Dissolved', 'First member', 'Second member']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1604.0, '19 March 1604', '9 February 1611', 'Sir James Scudamore', 'Sir Herbert Croft']
SQL:

assistant: SELECT COUNT("Second member") FROM "Table" WHERE "First member" = 'John Rudhale';