n, m = map(int, input().split())
a = [int(input()) for _ in range(m)]
b = [0, 1]
c = []
ans = 1

for _ in range(n):
    b.append(b[-1] + b[-2])

c.append(a[0])
for i in range(m - 1):
    c.append(a[i + 1] - a[i] - 1)
c.append(n - a[m - 1])

for i in c:
    ans *= b[i]

print(ans % 1000000007)
