The string $$$t_1t_2 \dots t_k$$$ is good if each letter of this string belongs to at least one palindrome of length greater than 1.
A palindrome is a string that reads the same backward as forward. For example, the strings A, BAB, ABBA, BAABBBAAB are palindromes, but the strings AB, ABBBAA, BBBA are not.
Here are some examples of good strings:
You are given a string $$$s$$$ of length $$$n$$$, consisting of only letters A and B.
You have to calculate the number of good substrings of string $$$s$$$.
The first line contains one integer $$$n$$$ ($$$1 \le n \le 3 \cdot 10^5$$$) — the length of the string $$$s$$$.
The second line contains the string $$$s$$$, consisting of letters A and B.
Print one integer — the number of good substrings of string $$$s$$$.
5 AABBB
6
3 AAA
3
7 AAABABB
15
In the first test case there are six good substrings: $$$s_1 \dots s_2$$$, $$$s_1 \dots s_4$$$, $$$s_1 \dots s_5$$$, $$$s_3 \dots s_4$$$, $$$s_3 \dots s_5$$$ and $$$s_4 \dots s_5$$$.
In the second test case there are three good substrings: $$$s_1 \dots s_2$$$, $$$s_1 \dots s_3$$$ and $$$s_2 \dots s_3$$$.
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