n,m = (int(x) for x in input().split())
a = []
for i in range(m):
    a.append(int(input()))

total = [0 for _ in range(n)]
one = [0 for _ in range(n)]
two = [0 for _ in range(n)]

if 1 not in a:
    one[0] = 1
if 2 not in a:
    one[1] = 1
    two[1] = 1
total[1] = one[1]+two[1]

for i in range(2,n):

    if (i+1) not in a:
        one[i] = total[i-1]
        two[i] = total[i-2]
        total[i] = one[i]+two[i]
        print(one[i],two[i],total[i])

print(total[-1] % 1000000007)