var a,b: integer; R: real; begin Readln(a); Readln(b); R:=(a*b)/(Sqr(a)-Sqr(b)) - b/(2*a-3*b); Writeln(R) end.
var X,R: real; begin Readln(X); R:=exp(ln(2)*X)/cos(X) + exp(ln(3)*X); Writeln(R) end.