# coding:UTF-8
import sys

MOD = 10 ** 9 + 7
INF = float('inf')

N, K = list(map(int, input().split()))     # スペース区切り連続数字
A = list(map(int, input().split()))     # スペース区切り連続数字

nums = set(A)

for a in A:
    if a == 2:
        if 1 not in nums and 7 in nums:
            print("No")
            exit()
    elif a == 3:
        if 2 not in nums and 8 in nums:
            print("No")
            exit()
        if 1 not in nums and 6 in nums:
            print("No")
            exit()
    else:
        if a - 1 not in nums and a + 5 in nums:
            print("No")
            exit()
        if a - 2 not in nums and a + 3 in nums:
            print("No")
            exit()
        if a - 3 not in nums and a + 1 in nums:
            print("No")
            exit()

print("Yes")