import java.util.HashMap;
import java.util.Map;

class ReservationSystem {
  private static final int MAX_CAPACITY = 12;
  private final Map<String, Integer> availabilityByDate = new HashMap<>();
  private final Map<String, Integer> reservations = new HashMap<>();

  public boolean request(String date, String name, String phone, int size) {
    int available = availabilityByDate.getOrDefault(date, MAX_CAPACITY);
    if (size < 1 || available < size) {
      return false;
    }
    reservations.put(date+name+phone, size);
    availabilityByDate.put(date, available - size);
    return true;
  }

  public void cancel(String date, String name, String phone) {
    var size = reservations.remove(date+ name+phone);
    if (size != null) {
      availabilityByDate.computeIfPresent(date, (d, c) -> c + size);
    }
  }
}