var
  now,n,i:longint;
  f:array[0..1000]of longint;

begin
  assign(input,'baga.in'); reset(input);
  assign(output,'baga.out'); rewrite(output);
  readln(n);
  f[0]:=1;
  f[1]:=1;
  f[2]:=5;
  now:=0;
  for i:=3 to n do
  begin
    f[now]:=f[(now+2) mod 3]+f[(now+1) mod 3]*4+f[now mod 3]*2;
    f[now]:=f[now] mod 997;
    if i=n then writeln(f[now]);
    now:=(now+1) mod 3;
  end;
  close(input);
  close(output);
end.