import sys

input = sys.stdin
N, W = input().split()
aArr = list()
ans = 0
tmp = int(N)
MOD = 10 ** 9 + 7
aArr = set(map(int, input()))

tmp = 0
tmpB = 0
ans = 1
for i in range(int(N)):
    if (i in aArr):
        tmp = 0
    elif i < 2:
        tmp = 1
    else:
        tmp = ans
    ans = (tmp + tmpB) % MOD
    tmpB = tmp
print(ans)
