import sys
from functools import lru_cache
sys.setrecursionlimit(1000000)
read=sys.stdin.read
N,M,*alst=map(int,read().split())
mod=10**9+7
dp = [1, 1 if 1 not in alst else 0]
@lru_cache(maxsize=None)
def a(n):
  if n==0:
    return dp[0]
  elif n==1:
    return dp[1]
  else:
    if n not in alst:
      return (a(n-2)+a(n-1))%mod
    else:
      return 0
print(a(100))
