rank nation gold silver bronze total
rank
nation
gold
silver
bronze
total
number
first second
number
number
number
number
number text(text) number number number number
1 united states (usa) 25 16 7 48
how many medals did the usa win ?
WRB JJ NNS VBD-AUX DT NNP VB .
48
select c6 from w where c2_second = 'usa'