来来考考大家改错，改一个地方就能通过

解题思路:

注意事项:

参考代码:

import java.util.Scanner;

public class Main {

 private static int count=0;

private static int[] a;

public static void main(String[] args) {

Scanner input=new Scanner(System.in);

int n=input.nextInt(),m=input.nextInt();

a=new int[n+1];

for(int i=0;i<m;i++){

int k=input.nextInt();

if(k<n);

a[k]=1;

}

 dfs(1,n);

 System.out.println(count);

}

private static void dfs(int i, int n) {

if(i>=n){

count++;

return;

}

if(i+1<=n&&a[i+1]!=1)

dfs(i+1,n);

if(i+2<=n&&a[i+2]!=1)

dfs(i+2,n);

}

}