rank nation gold silver bronze total
rank
nation
gold
silver
bronze
total
number
number
number
number
number
number text number number number number
1 united states 12 13 6 31
what country with more than 20 total medals has the least amount of silver medals ?
WDT NN IN JJR IN CD JJ NNS VBD-AUX DT JJS NN IN NN NNS .
Russia
select c2 from w where c6_number > 20 order by c4_number asc limit 1