题解 | 小美的排列询问

n = int(input())
arr = list(map(int,input().split()))
x,y = map(int,input().split())
if x not in arr or y not in arr:
    print('No')
if arr[arr.index(x)-1] == y or arr[arr.index(x)+1] == y:
    print('Yes')
else:
    print('No')