Var
 x:real;

Function Fib(z:real):Integer;
var
 i,fb,Sum,a1,a2:Word;
begin
 if z<1 then
  Fib:=1
 else
 if z<2 then
 Fib:=-1
 else
  begin
   Sum:=2;
   a1:=1;
   a2:=1;
   i:=2;
   repeat
    a2:=a1+a2;
    a1:=a2-a1;
    Sum:=Sum+a2;
    i:=i+1;
   until 1.0*Sum>z;
   if (i mod 2)=0 then Fib:=-1 else Fib:=1;
  end;
end;

Begin
 Repeat
  Write('x= ');
  Readln(x);
  If x<0 then Writeln('x out of range!');
 Until x>=0;
 Writeln('y= ',Fib(x));
 Readln;
End.