var
x,j,f,c,c0:real;
i:longint;
h:integer;
begin
readln(x);
c:=1;c0:=0;f:=1;
h:=1;i:=0;j:=1;
while abs(c-c0)>1E-6 do begin
c0:=c;
f:=f*sqr(x);
j:=j*(i+1)*(i+2);
i:=i+2;
h:=-h;
c:=c+h*f/j;
end;
writeln(c:10:6);
readln;
end.
var
x,j,f,c,c0:real;
i:longint;
h:integer;
begin
readln(x);
c:=1;c0:=0;f:=1;
h:=1;i:=0;j:=1;
while abs(c-c0)>1E-6 do begin
c0:=c;
f:=f*sqr(x);
j:=j*(i+1)*(i+2);
i:=i+2;
h:=-h;
c:=c+h*f/j;
end;
writeln(c:10:6);
readln;
end.