N, M = map(int,input().split())
As = []
for i in range(M):
	As.append(int(input()))

count = 0
def search(current):
	global count
	if current in As:
		return
	if current > N:
		return
	if current == N:
		count += 1
		return
	search(current + 1)
	search(current + 2)

search(0)
print(count % 1000000007)
