N,M=map(int,input().split())
L=[int(input()) for _ in range(M)]
ans=0
def dfs(i):
	global ans
	if i==N:
		ans+=1
		# print(i)
		return True
	if i>N:return False
	if i in L:return False
	dfs(i+1)
	dfs(i+2)

dfs(0)
print(ans%1000000007) 