#include <iostream>
#include <cstdio>

using namespace std;

typedef long long ll;

const int N = 2000010;

char s[N];
int n, g[N];
ll f[N];

int main() {
	cin >> n >> (s + 1);
	ll cnt = 0;
	for (int i = 1; i <= n; i ++ ) {
		int j = i - 1;
		while (s[i] != s[j] && j > 0) j = g[j] - 1;
		if (j > 0) g[i] = j;
	}
	for (int i = 1; i <= n; i ++ ) {
		if (g[i] > 0) f[i] = f[g[i] - 1] + 1;
		cnt += f[i];
	}
	printf("%lld\n", cnt);
	return 0;
}