Strange....

```
class Solution(object):
def checkRecord(self, n):
dp = [[0, 0, 0] for i in range(n)]
dp[0] = [1, 1, 0]
for i in range(n):
if i == 0:
continue
dp[i][0] = sum(dp[i - 1]) % 1000000007
dp[i][1] = dp[i - 1][0]
dp[i][2] = dp[i - 1][1]
res = [1]
res.extend([sum(x) % 1000000007 for x in dp])
count = res[n]
for i in range(n):
front = i - 0
back = n - i - 1
count += res[front] * res[back]
count = count % 1000000007
return count
```