event performance athlete nation place date
event
performance
athlete
nation
place
date
number hour min sec
list length
address
number parsed year month day
text time <n,text> text address date
100 m 3:34:14 usain bolt jamaica new york city ny, usa may 31
what is the number of countries listed in the table
WP VBD-AUX DT NN IN NNS VBN IN DT NN
4
Keyword Keyword Keyword Keyword Column Keyword Keyword Keyword
select count ( distinct c4 ) from w
None None Keyword Keyword Keyword Column None None None None
['agg', 'agg_count'] ['agg', 'agg_count'] ['agg', 'agg_count'] c4