import sys
input = sys.stdin.readline
n,m=(int(i) for i in input().split())
a = [int(input()) for i in range(m)]
#print(n,m,a)

d=[0 for i in range(100000+10)]
p=1000000007
n=100
#a=[1, 23, 45, 67, 89]

d[0]=1
if a.count(1) == 0:
    d[1]=1
else:
    d[1]=0
    
if a.count(2) == 0:
    d[2]=d[1]+d[0]
else:
    d[2]=0
    
for i in range(2,n+1):
    if a.count(i) == 0:
        d[i]=d[i-1]+d[i-2]
        d[i]=d[i]%p
    else:
        d[i]=0
#print(d)

print(d[100]%p)