#include <iostream>
#include <string>

using namespace std;

int main() {
	int n;
	string s;
	cin >> n >> s;
	int ans = 0;
	for (int c = 1; c <= s.length(); c++) {
		for (int i = 0; i + c <= s.length(); i++) {
			int d = 0;
			for (int j = 0; j < c; j++) {
				if (s[i+j] == s[i+c-1-j]) {
					d++;
				}
			}
			if (c == d) {
				ans++;
			}
		}
	}
	cout << ans << endl;
}