N, K = map(int, input().split())
A = list(map(int, input().split()))
U = 10 ** 5

B = []
C = []
for a in A:
    if a < U:
        B.append(a)
    elif a > U - 100:
        C.append(a)

ans = "Yes"
dp = [0] * (N + 10)
for a in B:
    dp[a] = 1
for i in reversed(range(N)):
    dp[i] |= (dp[i+1] & dp[i+6])
    dp[i] |= (dp[i+2] & dp[i+5])
    dp[i] |= (dp[i+3] & dp[i+4])
if dp[1]:
    ans = "No"

for x in C:
    for y in C:
        if abs(x - y) in [1, 3, 5]:
            ans = "No"
print(ans)