import java.util.Scanner;

public class ExplorersCivics {
	
    public static long parking(int n)
    {
       // Precondition:  n >= 0
       // Postcondition:  return the number of ways to fill n spots
       //   with Explorers and Civics if Civics take one spot and  Explorers take two spots.
       //   Civics are indistinguishable; Explorers are indistinguishable.


       if (n == 0) return 1;	// empty set
       else if (n == 1) return 1;        // one civic
       else return parking (n-1)  // civic in last position
                 + parking (n-2); // explorer in last position
    }

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner Input = new Scanner(System.in);
		int n;
		do{
		 System.out.println("Enter lot size n >= 0  (-1 to finish)");
		 n = Input.nextInt();
		 long[] A = new long[n+1];
		 if(n>=0){
			System.out.println("Parking in lot size " + n + ", number of possibilities " + parking(n));
		 }
		} while (n>=0);
	}

}