program function1;
declare a,b:integer;
   function func1():integer;
   declare res:integer;
   begin
      if a=0 then
         res:=10;
      else
         res:=20;
      end;
      b:=res; 
   end func1;

begin
   read(a);
   b:=func1();
   write(func1());
end function1.