program shx(input, output);
const eps=0.0000000000001;
var y,x,a:real;
    k:integer;
begin
    write('vvedite x:'); read(x);
    y:=x; k:=2; a:=y;
    while abs(a)>=eps do
       begin
      a:=a*x*x/k/(k+1); y:=y+a; k:=k+2 end;
      writeln('sh=',y:1:4)
end.