let solve n =
  let rec inner m acc3 acc5 =
    if 3*m > n && 5*m > n then (acc3, acc5)
    else if 3*m > n then inner (m+1) acc3 (acc5 + 2)
    else if 5*m > n then inner (m+1) (acc3 + 2) acc5
    else inner (m+1) (acc3 + 2) (acc5 + 2)
  in
  let x, y = inner 1 0 0 in
  print_int (x + y)

let _ =
  let n = int_of_string @@ read_line() in
  solve n