Switzerland 's tennis player Roger Federer , right .
Czech Republic 's Tomas Berdych , left , pose for a photo during a exhibition match on Vltava river in Prague , Czech Republic , Monday , Feb. 20 , 2017 .
Switzerland 's tennis player Roger Federer , right , and Czech Republic 's Tomas Berdych , left , pose for a photo during a exhibition match on Vltava river in Prague , Czech Republic , Monday , Feb. 20 , 2017 .