Please keep the MOD value 10^9 + 7 !
I had a bug in my code cauz I had the MOD value set to 10^9 + 7 and it was 10^9 + 9 in the problem -_-
For problem setters
Please keep the MOD value 10^9 + 7 !
I had a bug in my code cauz I had the MOD value set to 10^9 + 7 and it was 10^9 + 9 in the problem -_-