#define _CRT_SECURE_NO_WARNINGS

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <limits>
#include <ctime>
#include <cassert>
#include <map>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <stack>
#include <queue>
#include <numeric>
#include <iterator>
#include <bitset>
#include <unordered_map>
#include <unordered_set>

using namespace std;
#define FOR(i,n) for(int i = 0; i < (n); i++)
#define sz(c) ((int)c.size())
#define ten(n) ((int)1e##n)
using ll = long long;
using Pii = pair<int, int>;
using Pll = pair<ll, ll>;

template<typename ...> static inline int getchar_unlocked(void) { return getchar(); }
template<typename ...> static inline void putchar_unlocked(int c) { putchar(c); }
#define mygc(c) (c)=getchar_unlocked()
#define mypc(c) putchar_unlocked(c)
void reader(int& x) { int k, m = 0; x = 0; for (;;) { mygc(k); if (k == '-') { m = 1; break; }if ('0' <= k&&k <= '9') { x = k - '0'; break; } }for (;;) { mygc(k); if (k<'0' || k>'9')break; x = x * 10 + k - '0'; }if (m) x = -x; }
void reader(ll& x) { int k, m = 0; x = 0; for (;;) { mygc(k); if (k == '-') { m = 1; break; }if ('0' <= k&&k <= '9') { x = k - '0'; break; } }for (;;) { mygc(k); if (k<'0' || k>'9')break; x = x * 10 + k - '0'; }if (m) x = -x; }
int reader(char c[]) { int i, s = 0; for (;;) { mygc(i); if (i != ' '&&i != '\n'&&i != '\r'&&i != '\t'&&i != EOF) break; }c[s++] = i; for (;;) { mygc(i); if (i == ' ' || i == '\n' || i == '\r' || i == '\t' || i == EOF) break; c[s++] = i; }c[s] = '\0'; return s; }
int reader(string& c) { int i; for (;;) { mygc(i); if (i != ' '&&i != '\n'&&i != '\r'&&i != '\t'&&i != EOF) break; }c.push_back(i); for (;;) { mygc(i); if (i == ' ' || i == '\n' || i == '\r' || i == '\t' || i == EOF) break; c.push_back(i); }; return sz(c); }
template <class T, class S> void reader(T& x, S& y) { reader(x); reader(y); }
template <class T, class S, class U> void reader(T& x, S& y, U& z) { reader(x); reader(y); reader(z); }
template <class T, class S, class U, class V> void reader(T& x, S& y, U& z, V & w) { reader(x); reader(y); reader(z); reader(w); }
void writer(int x, char c) { int s = 0, m = 0; char f[10]; if (x<0)m = 1, x = -x; while (x)f[s++] = x % 10, x /= 10; if (!s)f[s++] = 0; if (m)mypc('-'); while (s--)mypc(f[s] + '0'); mypc(c); }
void writer(ll x, char c) { int s = 0, m = 0; char f[20]; if (x<0)m = 1, x = -x; while (x)f[s++] = x % 10, x /= 10; if (!s)f[s++] = 0; if (m)mypc('-'); while (s--)mypc(f[s] + '0'); mypc(c); }
void writer(const char c[]) { int i; for (i = 0; c[i] != '\0'; i++)mypc(c[i]); }
void writer(const string& x, char c) { int i; for (i = 0; x[i] != '\0'; i++)mypc(x[i]); mypc(c); }
void writer(const char x[], char c) { int i; for (i = 0; x[i] != '\0'; i++)mypc(x[i]); mypc(c); }
template<class T> void writerLn(T x) { writer(x, '\n'); }
template<class T, class S> void writerLn(T x, S y) { writer(x, ' '); writer(y, '\n'); }
template<class T, class S, class U> void writerLn(T x, S y, U z) { writer(x, ' '); writer(y, ' '); writer(z, '\n'); }
template<class T, class S, class U, class V> void writerLn(T x, S y, U z, V v) { writer(x, ' '); writer(y, ' '); writer(z, ' '); writer(v, '\n'); }
template<class T> void writerArr(T x[], int n) { if (!n) { mypc('\n'); return; }FOR(i, n - 1)writer(x[i], ' '); writer(x[n - 1], '\n'); }
template<class T> void writerArr(vector<T>& x) { writerArr(x.data(), (int)x.size()); }

template<class T> void chmin(T& a, const T& b) { if (a > b) a = b; }
template<class T> void chmax(T& a, const T& b) { if (a < b) a = b; }

template<class T> T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }
template<class T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
ll mod_pow(ll a, ll n, ll mod) {
	ll ret = 1;
	ll p = a % mod;
	while (n) {
		if (n & 1) ret = ret * p % mod;
		p = p * p % mod;
		n >>= 1;
	}
	return ret;
}
template<class T> T extgcd(T a, T b, T& x, T& y) { for (T u = y = 1, v = x = 0; a;) { T q = b / a; swap(x -= q * u, u); swap(y -= q * v, v); swap(b -= q * a, a); } return b; }
ll mod_inv(ll a, ll m) { ll x, y; extgcd<ll>(a, m, x, y); return (m + x % m) % m; }

template<int a, int m>
struct hasher {
public:
	struct X {
		int hash;
		int len;
		X() : hash(0), len(0) {}
		X(int hash, int len) : hash(hash), len(len) {
			this->hash %= m;
			if (this->hash < 0) this->hash += m;
		}
	};
	const int n;
	vector<int> mtbl;
	vector<int> h, rh;

	hasher(const string& s) : n(sz(s)), mtbl(sz(s) + 1), h(sz(s) + 1), rh(sz(s) + 1) {
		h[0] = rh[0] = 0;
		FOR(i, n) h[i + 1] = (ll(h[i]) * a + s[i]) % m;
		FOR(i, n) rh[i + 1] = (ll(rh[i]) * a + s[n - i - 1]) % m;
		mtbl[0] = 1;
		FOR(i, n) mtbl[i + 1] = ll(mtbl[i]) * a % m;
	}
	X substr(int l, int r) const {
		assert(l <= r);
		return X(ll(h[r] - ll(h[l]) * mtbl[r - l]) % m, r - l);
	}

	X revsubstr(int l, int r) const {
		assert(l <= r);
		return X(ll(rh[n - l] - ll(rh[n - r]) * mtbl[r - l]) % m, r - l);
	}
	// l + r
	X add(X l, X r) const {
		X ret;
		ret.hash = (ll(l.hash) * mtbl[r.len] + r.hash) % m;
		ret.len = l.len + r.len;
		return ret;
	}
};

using H1 = hasher<ten(8) + 7, ten(9) + 7>;
using H2 = hasher<ten(8) + 7, ten(9) + 9>;

const int M1 = ten(9) + 7, M2 = ten(9) + 9;
const int H = ten(8) + 7;

struct P {
	int l, r;
};

P add(const P& p, char c) {
	P ret;
	ret.l = (ll(p.l) * H + c) % M1;
	ret.r = (ll(p.r) * H + c) % M2;
	return ret;
}

ll toLL(const P& p) {
	return (ll(p.l) << 32) + p.r;
}

ll ans = 0;
void dfs(string& s, int dep, const pair<P, P> cur, map<Pll, int>& um, bool check) {
	if (sz(s) == dep * 2) {
		ll l = toLL(cur.first);
		ll r = toLL(cur.second);
		if (!check) {
			um[Pll(l, r)]++;
		} else {
			ans += um[Pll(l, r)];
		}
	} else {
		char c = s[dep];
		pair<P, P> nt = cur;
		nt.first = add(cur.first, c);
		dfs(s, dep + 1, nt, um, check);
		nt = cur;
		nt.second = add(cur.second, c);
		dfs(s, dep + 1, nt, um, check);
	}
}

int main() {
	int n; reader(n);
	string s; reader(s);
	H1 h1(s);
	H2 h2(s);

	map<Pll, int> m1;
	pair<P, P> cur;
	cur.first.l = cur.first.r = 0;
	cur.second.l = cur.second.r = 0;
	dfs(s, 0, cur, m1, false);
	reverse(s.begin(), s.end());
	dfs(s, 0, cur, m1, true);

	writerLn(ans);

	return 0;
}


Measured memory_bytes: 33024