import sys
sys.setrecursionlimit(100000)

def intinput(): return map(int,sys.stdin.readline().split())


n, m = intinput()
a = {int(sys.stdin.readline()) for _ in range(m)}
print(a)
memo = [0 for x in range(n + 4)]
memo[0] = 1
mod = 10 ** 9 + 7
for i in range(n):
    if i + 1 not in a:
        memo[i + 1] = (memo[i + 1] + memo[i]) % mod
    if i + 2 not in a:
        memo[i + 2] = (memo[i + 2] + memo[i]) % mod