N, M = list(map(int, input().split()))
a = []
for _ in range(M):
    a.append(int(input()))
a = sorted(list(set(a)))
dif = [a[0]-1]
dif.extend([(a[i]-1)-(a[i-1]+1) for i in range(1,len(a))])
dif.extend([N-a[-1]-1])
max_dif = max(dif)
Fiblist = {-1:0,0:1,1:1,2:2}
for n in range(3,max_dif+1):
    Fiblist[n]=Fiblist[n-1]+Fiblist[n-2]
ans = 1
for part in dif:
    ans= ans*Fiblist[part]%1000000007
print(ans)