N,M = map(int,input().split())
a = [True]*(N+1)
for _ in range(M):
  b = int(input())
  a[b] = False

mod = 10**9+7
dp = [0]*(N+1)
dp[0] = 1
for i in range(N):
  for j in range(i+1,min(i+2,N)+1):
    if a[j]:
      dp[j] += dp[i]
      dp[j] %= mod


print(dp)