#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e6 + 7;
const int mod = 51123987;
const int inv2 = mod + 1 >> 1;
struct Edge {
  int to, last, v;
} E[maxn];
int fa[maxn];
int len[maxn];
int dep[maxn];
int head[maxn];
int tot;
int last;
int cnt;
int n;
char s[maxn];
int pre[maxn];
long long suf[maxn];
void Init() {
  for (int i = 0; i <= tot; ++i) {
    fa[i] = len[i] = dep[i] = 0;
    head[i] = 0;
  }
  cnt = 0;
  fa[last = 0] = fa[tot = 1] = 1;
  len[1] = -1;
}
int Getfail(int x, int ed) {
  while (s[ed] ^ s[ed - len[x] - 1]) x = fa[x];
  return x;
}
int Check(int x, int v) {
  for (int i = head[x], y; y = E[i].to, i; i = E[i].last)
    if (E[i].v == v) return E[i].to;
  return 0;
}
void Adde(int x, int y, int z) {
  E[++cnt] = (Edge){y, head[x], z};
  head[x] = cnt;
}
void Extend(int x, int ed) {
  int p = Getfail(last, ed);
  int np = Check(p, x);
  if (!np) {
    np = ++tot;
    int pp = Getfail(fa[p], ed);
    fa[np] = Check(pp, x);
    Adde(p, np, x);
    len[np] = len[p] + 2;
    dep[np] = dep[fa[np]] + 1;
  }
  last = np;
}
int main() {
  Init();
  scanf("%d", &n);
  scanf("%s", s + 1);
  for (int i = 1; i <= n; ++i) Extend(s[i] - 'a', i), pre[i] = dep[last];
  Init();
  reverse(s + 1, s + n + 1);
  for (int i = 1; i <= n; ++i)
    Extend(s[i] - 'a', i), suf[n - i + 1] = dep[last];
  for (int i = n; i; --i) suf[i] += suf[i + 1], suf[i] %= mod;
  int ans = 0;
  for (int i = 1; i <= n; ++i) (ans += 1LL * pre[i] * suf[i + 1] % mod) %= mod;
  int sum = 1LL * suf[1] * (suf[1] - 1) / 2 % mod;
  ans = (sum - ans) % mod;
  ans < 0 ? ans += mod : 0;
  printf("%d\n", ans);
  return 0;
}
