Frequency count in pig

[jamal sasha]

Hi,

   My data is in format:

   user_id,movie_id,timestamp
    123, abc,unix_timestamp
    123, def, ...
    123, abc, ...
    234, sda, ...


Now, I want to compute the number of times each movie is played in pig..
So the output I am expecting is:

   123,abc,2
   123,def,1
   234,sda,1

  and so on..
how do i do this in pig