A11202 | Bark to Unlock

As technologies develop, manufacturers are making the process of unlocking a phone as user-friendly as possible. To unlock its new phone, Arkady's pet dog Mu-mu has to bark the password once. The phone represents a password as a string of two lowercase English letters.

Mu-mu's enemy Kashtanka wants to unlock Mu-mu's phone to steal some sensible information, but it can only bark $n$ distinct words, each of which can be represented as a string of two lowercase English letters. Kashtanka wants to bark several words (not necessarily distinct) one after another to pronounce a string containing the password as a substring. Tell if it's possible to unlock the phone in this way, or not.

The first line contains two lowercase English letters — the password on the phone.

The second line contains single integer $n$ ( $1<=n<=100$ ) — the number of words Kashtanka knows.

The next $n$ lines contain two lowercase English letters each, representing the words Kashtanka knows. The words are guaranteed to be distinct.

Print "YES" if Kashtanka can bark several words in a line forming a string containing the password, and "NO" otherwise.

You can print each letter in arbitrary case (upper or lower).