var i,n,jpr,t,o,aux:longint;
    ch:string[1];
    b,a:array[1..1500] of shortint;
    l:integer;

procedure inmultire;
var ipr:longint;
begin
for ipr:=n downto 1 do
  begin
   inc(o);
   b[o]:=(8*a[ipr]+t) mod 10;
   t:=(8*a[ipr]+t) div 10;
  end;
while t<>0 do
  begin
   inc(o);
   b[o]:=t mod 10;
   t:=t div 10;
  end;
end;

begin
assign(input,'sarpe.in');
assign(output,'sarpe.out');
reset(input);
rewrite(output);
while not eof do
  begin
   while not eoln do
     begin
      read(ch);
      inc(n);
      val(ch,a[n],l);
     end;
  end;
if (a[n]=1) and (n=1) then
  begin
   write(2);
   halt;
  end;
close(input);
close(output);
end.