let () =
  Scanf.scanf "%d\n" @@ fun n ->
  let ans = ref 0 in
  for t = (n/5) downto 0 do
    for g = 0 to t do
      let nn = n - t * 5 - g * 2 in
      if nn >= 0 && nn mod 3 = 0 then ans := !ans + 1; 
    done;
  done;
  Printf.printf "%d\n" !ans