from operator import itemgetter
from itertools import *
from bisect import *
from collections import *
from heapq import *
import sys

sys.setrecursionlimit(10**6)
int1 = lambda x: int(x)-1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.buffer.readline())
def MI(): return map(int, sys.stdin.buffer.readline().split())
def MI1(): return map(int1, sys.stdin.buffer.readline().split())
def LI(): return list(map(int, sys.stdin.buffer.readline().split()))
def LI1(): return list(map(int1, sys.stdin.buffer.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.buffer.readline()[:-1]
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
dij = [(1, 0), (0, 1), (-1, 0), (0, -1)]

def solve(aa):
    fin=set(aa)
    aa=[-a for a in aa]
    heapify(aa)
    q=deque()
    sep=-100
    while aa:
        a=-heappop(aa)
        if len(q)==4:q.pop()
        # print(a,aa,q)
        if a==1:return False
        if a<1:return True
        if a+5 in q:
            sep=a-9
            if a-1 not in fin:
                heappush(aa,-a+1)
                fin.add(a-1)
        if a+3 in q:
            sep=a-5
            if a-2 not in fin:
                heappush(aa, -a+2)
                fin.add(a-2)
        if a+1 in q:
            sep=a-8
            if a-3 not in fin:
                heappush(aa,-a+3)
                fin.add(a-3)
        if sep>=1:return False
        q.appendleft(a)
    return True

n,k=MI()
aa=LI()
if solve(aa):print("Yes")
else:print("No")