import sys
sys.setrecursionlimit(10000000)
n, m = map(int, sys.stdin.readline().split())
A = [int(sys.stdin.readline()) for _ in range(m)]

cnt=0
def calc(d):
    if d >=n:
        if d ==n:
            global cnt
            cnt+=1
        return
    if d in A:
        return
    else:
        calc(d+1)
        calc(d+2)



calc(0)
print(cnt%1000000007)