def calc_Stairs_Patterns(num):
    if num >= 2:
        return calc_Stairs_Patterns(num - 1) + calc_Stairs_Patterns(num - 2)
    elif num == -1:
        print(0)
        exit()
    else:
        return 0
N, M = map(int,input().split())
data = []
for i in range(M):
    data.append(int(input()))
ans = 1
stair = 0
for i in data:
    ans *= calc_Stairs_Patterns(i  - 1 - stair)
    stair = i + 1
ans *= calc_Stairs_Patterns(N - stair)
print(ans % 1000000007)