#include <bits/stdc++.h>
#include <bits/extc++.h>
#define debug(...) fprintf(stderr, __VA_ARGS__);
using namespace std;
using namespace __gnu_pbds;

typedef long long LL;
typedef unsigned long long ULL;
const int P = 998244353;
mt19937 rnd(time(0));

struct Mat {
  int x[2][2];
  Mat(int a = 0, int b = 0, int c = 0, int d = 0) {
    x[0][0] = a, x[0][1] = b, x[1][0] = c, x[1][1] = d;
  }
  void gen() {
    for (int i = 0; i < 2; i++) for (int j = 0; j < 2; j++)
        x[i][j] = rnd() % P;
  }
  bool pd() {
    return x[0][0] == 1 && !x[0][1] && !x[1][0] && x[1][1] == 1;
  }
  friend Mat operator*(const Mat &a, const Mat &b) {
    Mat c;
    for (int i = 0; i < 2; i++) for (int j = 0; j < 2; j++)
      for (int k = 0; k < 2; k++)
        (c.x[i][j] += LL(a.x[i][k]) * b.x[k][j] % P) %= P;
    return c;
  }
  friend Mat qp(Mat a, LL b = P - 2) {
    Mat res(1, 0, 0, 1);
    while (b) {
      if (b & 1) res = res * a;
      a = a * a;
      b /= 2;
    }
    return res;
  }
  ULL Hash() {
    ULL res = 0;
    for (int i = 0; i < 2; i++) {
      ULL tmp = ULL(x[i][0]) * x[i][1];
      res ^= tmp;
    }
    return res;
  }
};

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int n;
  string s;
  cin >> n >> s;
  vector<Mat> mat(26), rmat(26);
  for (int i = 0; i < 26; i++) {
    Mat t;
    t.gen();
    while (!qp(t, P - 1).pd()) t.gen();
    mat[i] = t;
    rmat[i] = qp(t);
  }
  Mat tag(1, 0, 0, 1);
  ULL tar = tag.Hash();
  vector<ULL> st(n + 1);
  for (int i = 0; i < n; i++) {
    st[i] = tar;
    tag = tag * (i & 1 ? rmat[s[i] - 'a'] : mat[s[i] - 'a']);
    tar = tag.Hash();
  }
  st[n] = tar;
  LL ans = 0;
  sort(st.begin(), st.end());
  for (int i = 0; i < st.size(); i++) {
    int j = i;
    while (j < st.size() && st[j] == st[i]) j++;
    ans += LL(j - i) * (j - i - 1) / 2;
    i = j - 1;
  }
  cout << ans << "\n";
  return 0;
}