A squared word is a word of the form $ xx $, i.e., consisting of a sequence of letters repeated twice. Some examples of squared words in English are the words: $ couscous $, $ murmur $ (= a low, continuous sound), $ tartar $ (= hardened dental plaque) and $ hotshots $. We would like to find out, for a given word, how many letters should be removed from the word for it to become a squared word (however, not necessarily a correct English word).

Input Format

The first line of the standard input contains an integer $ n $ (1 ≤ $ n $ ≤ 1000), denoting the length of the word. The second line contains a word consisting of $ n $ lower case English letters.

Output Format

The first and only line of the standard output should contain a single integer - the minimal number of letters that should be removed from the word for it to become a squared word. We assume that the empty word is a correct squared word.

Example

Input

15
tachystoskopach

Output

7

Notes

If we remove the letters y, s, o, s, k, o and p, we obtain a squared word tachtach. In Polish, this word represents a (not really well known) kind of a coach.