// 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); // 注意 hasNext 和 hasNextLine 的区别 int n = in.nextInt(); int[] a = new int [n+1]; for(int i=1;i<n+1;i++) a[in.nextInt()] = i; int x = in.nextInt(); int y = in.nextInt(); if(a[x] - a[y] == 1 || a[y] - a[x] == 1) System.out.println("Yes"); else System.out.println("No"); } }