#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2000005;
char str[MAXN];
struct Palindromic_Tree {
  vector<pair<int, int>> next[MAXN];
  int fail[MAXN];
  int cnt[MAXN];
  int num[MAXN];
  int len[MAXN];
  int S[MAXN];
  int last;
  int n;
  int p;
  int newnode(int l) {
    next[p].clear();
    cnt[p] = 0;
    num[p] = 0;
    len[p] = l;
    return p++;
  }
  void init() {
    p = 0;
    next[0].clear();
    next[1].clear();
    newnode(0);
    newnode(-1);
    last = 0;
    n = 0;
    S[n] = -1;
    fail[0] = 1;
  }
  int get_fail(int x) {
    while (S[n - len[x] - 1] != S[n]) x = fail[x];
    return x;
  }
  int find(int cur, int c) {
    for (int i = 0; i < next[cur].size(); i++) {
      if (next[cur][i].first == c) return next[cur][i].second;
    }
    return 0;
  }
  int add(int c) {
    c -= 'a';
    S[++n] = c;
    int cur = get_fail(last);
    int k = find(cur, c);
    if (k == 0) {
      int now = newnode(len[cur] + 2);
      fail[now] = find(get_fail(fail[cur]), c);
      next[cur].push_back(make_pair(c, now));
      num[now] = num[fail[now]] + 1;
    }
    last = find(cur, c);
    cnt[last]++;
    return num[last];
  }
  void count() {
    for (int i = p - 1; i >= 0; --i) cnt[fail[i]] += cnt[i];
  }
} tree;
long long head[MAXN], tail[MAXN];
int main() {
  int n;
  while (~scanf("%d", &n)) {
    memset(head, 0, sizeof(head));
    memset(tail, 0, sizeof(tail));
    scanf("%s", str + 1);
    tree.init();
    for (int i = 1; i <= n; i++) {
      tail[i] = tree.add(str[i]);
    }
    tree.init();
    for (int i = n; i >= 1; i--) {
      head[i] = ((head[i + 1] + tree.add(str[i])) % 51123987) % 51123987;
    }
    long long ans = head[1] * (head[1] - 1) / 2 % 51123987;
    for (int i = 2; i <= n; i++)
      ans = (ans - tail[i - 1] * head[i] % 51123987) % 51123987;
    ans = (ans + 51123987) % 51123987;
    printf("%lld\n", ans);
  }
  return 0;
}
