def main1(n,k,a):
  pre=a[-1]
  idx=0
  for i in reversed(range(k-1)):
    pre,now=a[i+1],a[i]
    if pre<40:
      idx=i
      break
    if pre-now in {1,3,5}:
        return False
  b=a[:idx+2]
  ary=[0]*(b[-1]+1)
  for x in b:ary[x]=1
  for i in reversed(range(1,b[-1]+1)):
    if i+6<b[-1]+1 and ary[i+1]==ary[i+6]==1:
      ary[i]=1
    if i+5<b[-1]+1 and ary[i+2]==ary[i+5]==1:
      ary[i]=1
    if i+4<b[-1]+1 and ary[i+3]==ary[i+4]==1:
      ary[i]=1
  return ary[1]==0

if __name__=='__main__':
  n,k=map(int,input().split())
  a=list(map(int,input().split()))
  flg1=main1(n,k,a)
  print('Yes' if flg1 else 'No')