Java 代码

import java.util.Scanner;

public class Main
{
    public static int count = 0;
    public static int stair = 0;

    public static void path (int k)
    {
        if (k == stair)
            count += 1;

        if (k > stair)
            return;

        path (k + 2);
        path (k + 1);
    }

    public static void main(String[] args)
    {
        Scanner cin = new Scanner(System.in);

        stair = cin.nextInt();

        path(0);

        System.out.println(count);
    }
}