import sys
N,M=map(int,input().split())
S=set(map(int,sys.stdin))

a,b=0,1
for i in range(1,N+1):
    if i in S:
        a,b=b,0
    else:
        a,b=b,a+b

print(b%(10**9+7)) import sys sys N,M=map(int,input().split()) N map(int,input().split()) map int input().split() ().split () input split M S=set(map(int,sys.stdin)) S set(map(int,sys.stdin)) set map(int,sys.stdin) map int sys.stdin sys stdin a,b=0,1 a 0 b 1 for i in range(1,N+1):
    if i in S:
        a,b=b,0
    else:
        a,b=b,a+b i range(1,N+1) range 1 N+1 N 1 if i in S:
        a,b=b,0
    else:
        a,b=b,a+b i in S i S a,b=b,0 a b b 0 a,b=b,a+b a b b a+b a b print(b%(10**9+7)) print b%(10**9+7) b 10**9+7 10**9 10 9 7 a,b=b,a+b b a M=map(int,input().split()) map(int,input().split()) M N,M=map(int,input().split()) map(int,input().split()) N S=set(map(int,sys.stdin)) set(map(int,sys.stdin)) S a,b=b,0 b a b=b,a+b a+b b b=0,1 1 b b=b,0 0 b a,b=0,1 0 a
import sys
N,M=map(int,input().split())
S=set(map(int,sys.stdin))

a,b=0,1
for i in range(1,N+1):
    if i in S:
        a,b=b,0
    else:
        a,b=b,a+b

print(b%(10**9+7))
