function partyTime(input = []) {
  let vipGuestsList = new Set();
  let regularGuestsList = new Set();
  let reservation;
  while ((reservation = input.shift()) !== "PARTY") {
    if (reservation[0] == Number(reservation[0])) {
      vipGuestsList.add(reservation);
    } else {
      regularGuestsList.add(reservation);
    }
  }

  for (let guest of input) {
    if (vipGuestsList.has(guest) || regularGuestsList.has(guest)) {
      if (guest[0] == Number(guest[0])) {
        vipGuestsList.delete(guest);
      } else {
        regularGuestsList.delete(guest);
      }
    }
  }

  console.log(vipGuestsList.size + regularGuestsList.size);
  vipGuestsList.forEach(el => console.log(el));
  regularGuestsList.forEach(el => console.log(el));
}