def fib_memo(n):
    """メモ化フィボナッチ"""
    memo = [0]*(n+1)

    def _fib(n):
        if n <= 1:
            return n
        if memo[n] != 0:
            return memo[n]
        memo[n] = _fib(n-1) + _fib(n-2)
        return memo[n]

    return _fib(n)
  
N, M = map(int, input().split())
A = list(map(int, input().split()))
B = [0]*(M-1)
for i in range(M):
  diff = 0
  if i == 0:
    diff = A[i] - 1
    B[0] = fib_memo(diff + 1)
  else if i == (M - 1):
    diff = N - A[M-1] -1
    B[M-1] = fib_memo(diff + 1)
  else:
    diff = A[i] - A[i-1]
    B[i] = fib_memo(diff + 1)
Ans = reduce(lambda a, b: a*b, B)
print(Ans % 1000000007)
    