program Task2;
var x: real;

function power(a, b:real):real;
begin
 power:=exp(b * ln(a));
end;

function y(f:real):real;
begin
 y:= power(3,-f) + cos(f) - sin(sqr(f));
end;

begin
 writeln('Type x:');
 readln(x);
 writeln(y(x):0:2);
end.