n,m=map(int, input().split())  #複数数値入力

import sys

sys.setrecursionlimit(10**20)

if m == 0:
    print(countWays_memo(n))
else:
    list_a = []
    for i in range(m):
        list_a.append(int(input()))

    def countWays_memo(n):
        memo = [-1]*(n+1)
        def _countWays(n):
            if n < 0:
                return 0
            elif n == 0:
                return 1
            else:
                if memo[n] > -1:
                    return memo[n]
                else:
                    memo[n] = _countWays(n-1) + _countWays(n-2) 
                    return memo[n]
        return _countWays(n)

    steps = [list_a[0]]
    now_step=list_a[0]+1
    for i in range(len(list_a)-1):
        steps.append(list_a[i+1]-now_step)
        now_step = list_a[i+1]+1
    steps.append(n-now_step+1)


    dict_steps = {}
    for s in set(steps):
        dict_steps[s] = steps.count(s)

    ans = 1
    for k,v in dict_steps.items():
        ans *= countWays_memo(k-1)**v

    print(ans% 1000000007)