rank nation gold silver bronze total
rank
nation
gold
silver
bronze
total
number
number
number
number
number
number text number number number number
1 south korea 9 2 1 12
how many nations have a total of 1 medal won ?
WRB JJ NNS VBD-AUX DT NN IN CD NN VBN .
9
select count ( c2 ) from w where c6_number = 1