Mancunian lives in the magical far-away land of Palindromia. Due to his patriotic nature, he wants each and every one of his friends' name to be a palindrome. Note that Mancunian's patriotism does not extend towards his own name.
To please him, each of his friends decide to change their name so that it becomes a palindrome. They can do that by choosing at most two non-overlapping substrings of their own name and reversing them.
Given a list of Mancunian's friends' names which consist only of lowercase letters, count the total number of friends who will be successful.

Input format

The first line contains two integers N and L, denoting the number of friends Mancunian has and the maximum length of a person's name in Palindromia respectively.
The \(ith\) of the next N lines contains a single string S denoting the name of the \(ith\) friend.

Output format

Print a single integer, which is the answer to the given problem.

Constraints

\(1 \le N \le 10\)
\(1 \le L \le 50\)