def Fib(n, memo={}):
    if n == 1:
        return 0
    elif n == 2:
        return 1
    elif n in memo:
        return memo[n]
    else:
        memo[n] = Fib(n-1, memo) + Fib(n-2, memo)
        return memo[n]
    
N, M = map(int, input().split())
A = [int(input()) for i in range(M)]

x=0
L=[]
for i in range(M):
    L += [A[i] - 1 - x]
    x = A[i] + 1
L += [N - x]
L = [Fib(i+2) for  i in L]

X=1
for i in range(len(L)):
    X=X*L[i]%1000000007
print(X)