mysql count group by having

I have this table:

Movies (ID, Genre)

A movie can have multiple genres, so an ID is not specific to a genre, it is a many to many relationship. I want a query to find the total number of movies which have at exactly 4 genres. The current query I have is

  SELECT COUNT(*) 
    FROM Movies 
GROUP BY ID 
  HAVING COUNT(Genre) = 4

However, this returns me a list of 4's instead of the total sum. How do I get the sum total sum instead of a list of count(*)?