# probability of '10' in seka for two players and one Joker in the Deck
scale=3 ;
p1=(4/21)*(17/20) + (1-4/21)*(16/20) ;
p2=(3/19)*(10/18) + (1-3/19)*(9/18) ;
p3=(3/17)*(5/16) + (1-3/17)*(4/16) ;
print (p1*p2*p3) ; print "\n" ;
halt ;