mod = 1000000007

def feb(n):
    if n==0:
        return 0
    if n==1:
        return 1
    else:
        return feb(n-1)+feb(n-2)
    # root = math.sqrt(5)
    # return int((1/root)*(((1+root)/2)**n - ((1-root)/2)**n))

def calculate(n, b):
    diff = [b[i+1] - b[i] - 1 for i in range(len(b)-1)]
    diff.insert(0, b[0])
    diff.append(n - b[-1])
    sum = 1
    for d in diff:
        if d == 0:
            return 0
        sum *= feb(d)%mod
        sum = sum%mod
    return sum


n, m = map(int, input().split())
b = []
for i in range(m):
    b.append(int(input()))

print(calculate(n, b))
