what countries took part in the 2012-13 fis snowboard world cup?
canada, united states, austria, japan, italy, france, australia, norway, slovenia, finland, germany, russia, switzerland, china, poland, czech republic, belgium, netherlands, spain, bulgaria, great britain, sweden
which countries won silver medals?
canada, united states, austria, japan, italy, france, australia, norway, slovenia, finland, germany, switzerland, china, poland, netherlands
out of those countries, which won the most silver medals?
austria