import sys

def fibo(n):
    a, b = 0, 1
    if n == 1:
        return 1
    else:
        for i in range(n):
            a0 = a
            a = b
            b = a0 + b
        return b
        
N, M = map(int, input().split())
a = []

for i in range(M):
    a.append(int(input()))
    
for j in range(len(a)-1):
    if a[j+1] - a[j] == 1:
        print(0)
        sys.exit()
    
hole = 0
pattern = 1

for a_ in a:
    hole = a_ - hole
    pattern *= fibo(hole-1)
    hole = a_
    
pattern *= fibo(N-hole-1)

print(pattern % 1000000007)