user: Question: How many episodes are there for the three darts challenge with Sharon Osbourne?
Columns: ['Episode Number', 'Air Date', 'Guests', 'Three Darts Challenge', 'Musical Performance']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2.0, '5 April 2010', 'Aaron Johnson , Patsy Palmer , Sharleen Spiteri', 'Joanna Lumley', 'Sharleen Spiteri - Xandu']
SQL:

assistant: SELECT COUNT("Episode Number") FROM "Table" WHERE "Three Darts Challenge" = 'Sharon Osbourne';