def fib(x):
    if x == 1:
        return 1
    a0 = 1
    a1 = 1
    for i in range(x-1):
        tmp = a1
        a1 = a0 + a1
        a0 = tmp
    return a1

n, m = map(int, input().split())
*a_list, = map(int, input().split())
a_list = a_list + [n]

count = 1
_a = 0
for a in a_list:
    num = a - _a - 1
    count = count * fib(num) % 1000000007
    _a = a
print(count)
  