var x,y:real;beginread(x);if x>3.5 then y:=sin(x)*(ln(x)/ln(10));if x<3.5 then y:=cos(2*x);write(y);end.
var x,y:real;
begin
read(x);
if x>3.5 then y:=sin(x)*(ln(x)/ln(10));
if x<3.5 then y:=cos(2*x);
write(y);
end.