n, m = map( int, input().split() )

a = [ int( input()) for _ in range( m )]

ans = 0
def dfs( i, s ):
  global ans
  if i == n:
    ans += 1
  elif i > n:
    return 0
  else:
    next_left = i + 1
    if not( next_left in a ):
      dfs( next_left, s + str( next_left ) )
    next_right = i + 2
    if not( next_right in a ):
      dfs( next_right, s + str( next_right ) )

dfs( 0, "0" )

print( ans % 1000000007 )
