/**
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**/
#define _FORTIFY_SOURCE 0
#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("fast-math")
#include <iostream>
#include <string>                 
#include <stdio.h>
#include <vector>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <deque>
#include <algorithm>
#include <math.h>
#include <time.h>
#include <random>
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define int long long
#define double long double
#define left left228
#define right right228 
#define x1 x1228 
#define y1 y1228
#define all(x) x.begin(), x.end()
       
using namespace std;
       
typedef long long ll;
typedef pair<int, int> pii;
mt19937 rnd(time(0));
                                                      
const int maxn = 3e5 + 7, mod = 1e9 + 7, inf = 1e18;
const double eps = 1e-9, pi = acos(-1);
int n;
string s;
	        
void solve() {
	cin >> n >> s; 
	int ans = 0; 
	for (int mask = 0; mask < (1 << n); ++mask) {
		string have = "";
		int bt[n]; 
		for (int i = 0; i < n; ++i) bt[n - i - 1] = (mask >> i) & 1; 
		int pp = 0; 
		for (int i = 0; i < n; ++i) {
			if (bt[i] == 0) {
				have += s[i]; 
				pp++;
			}
		}
		for (int i = n - 1; i >= 0; --i) {
			if (bt[i] == 1) {
				have += s[i]; 
			}
		}
		int dp[n + 1][n + 1]; 
		for (int i = 0; i < n + 1; ++i) {
			for (int j = 0; j < n + 1; ++j) dp[i][j] = 0; 
		}
		int p1 = pp;
		int p2 = n - (n - pp) - 1;
		if (s[n] == have[p1]) {
			dp[1][1] = 1;
		} 
		if (s[n] == have[p2]) {
			dp[1][0] = 1; 
		} 
		for (int i = 2; i <= n; ++i) {
			for (int j = 0; j <= n; ++j) {
				if (i < j) continue;
				int p10 = p1 + j - 1;
				int p20 = p2 - (i - j) + 1;
				if (p10 < 2 * n && have[p10] == s[n + i - 1] && j > 0) {
					dp[i][j] += dp[i - 1][j - 1]; 					
				} 
				if (p20 >= 0 && have[p20] == s[n + i - 1]) {
					dp[i][j] += dp[i - 1][j]; 
				}
			}
		}
		ans += dp[n][n - pp]; 
	}    
	cout << ans; 
}                                
   
signed main() {
//  freopen("string.in", "r", stdin);
//  freopen("string.out", "w", stdout);
    #ifdef offline_judge
        freopen("TASK.in", "r", stdin);
        freopen("TASK.out", "w", stdout);
    #endif      
    srand(time(0)); 
    cout.precision(10);
    cout << fixed;
    ios_base::sync_with_stdio(false);
    cin.tie(0); 
    solve();
    return 0;                                        
}

Measured memory_bytes: 384