import sys

MOD=10**9+7
N,M=map(int,input().split())
bad=set(map(int,sys.stdin))

a,b=0,1
for i in range(1,N+1):
    if i in bad:
        a,b=b,0
        if a==0:
            break
    else:
        a,b=b,(a+b)%MOD

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

MOD=10**9+7
N,M=map(int,input().split())
bad=set(map(int,sys.stdin))

a,b=0,1
for i in range(1,N+1):
    if i in bad:
        a,b=b,0
        if a==0:
            break
    else:
        a,b=b,(a+b)%MOD

print(b)
