panda-and-palindrome
Source: hackerearth
Difficulty: UNKNOWN_DIFFICULTY

Panda is an artist and he is obsessed with palindromic number . He want to count  the number of palidromic number can be generated by resuffling of any contiguous substring of given numberic string.Please Help panda by contributing your code.

Input : 
First Line contain an Integer N (size of String).
Second Line contain Given string. 

Output:
Output a single integer according to question.

Note:-  All Single Digit number are palindromic number.

Constraints
1 ≤ N ≤ 10^5  

SAMPLE INPUT
5
12121

SAMPLE OUTPUT
11

Explanation

Generated palindromic number by reshuffling substring.   
[1],[121],[1212],[12121],
[2],[212],[2121],
[1],[121],
[2],
[1] .