#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define pii pair<int,int>
#define pp pair<pair<ll, ll>,pair<ll, ll>>
#define pll pair<ll,ll>
#define pdd pair<double,double>
#define vii vector<int>
#define vll vector<ll>
#define mat vector<vector<ll>>
#define lb lower_bound
#define pb push_back
#define fi first
#define sc second
#define rep(i,n) for(ll i=0;i<n;i++)
#define rep2(i,a,b) for(ll i=a;i<b;i++)
#define repr(i,n) for(ll i=n-1;i>=0;i--)
#define all(x) x.begin(),x.end()
#define pq priority_queue<ll>
#define pqg priority_queue<ll,vector<ll>,greater<ll>>
#define LB(v,x) (lower_bound(v.begin(),v.end(),x)-v.begin())
#define UB(v,x) (upper_bound(v.begin(),v.end(),x)-v.begin())
#define ERASE(v) sort(v.begin(),v.end());v.erase(unique(v.begin(),v.end()),v.end())
// #define int ll
using namespace std;
const ll INF = (1 << 30 ) - 1;
const ll LLINF = (1LL << 60LL);
const ll MOD = 1000000007;
const ll mod = 998244353;
const ll MAX = 1100000;
const double pi = acos(-1);
const double eps = 1e-10;
ll dx[4] ={1,0,-1,0} , dy[4] ={0,1,0,-1};
 
 
struct Timer{
    chrono::system_clock::time_point start, end;
    Timer(){ start = chrono::system_clock::now(); }
    ~Timer(){
        end = chrono::system_clock::now();
        auto msec = chrono::duration_cast<chrono::milliseconds>(end - start).count();
        cerr<<"time : "<<msec<<" ms"<<endl;
    }
};
 
 



signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(15);
    Timer TM;
    

    ll n;
    ll ans=0;
    string s;
    // unordered_map<string,ll> mp;
    map<pair<string,string>,ll> mp;
    cin>>n>>s;
    rep(bit,(1<<n)){
        string u="",t="";
        rep(i,n){
            if(bit&(1<<i)){
                u+=s[i];
            }
            else t+=s[i];
        }
        ++mp[make_pair(u,t)];
        // cout<<u+'0'+t<<endl;
    }
    rep(bit,(1<<n)){
        string u="",t="";
        rep(i,n){
            if(bit&(1<<i)){
                u=s[i+n]+u;
            }
            else t=s[i+n]+t;
        }
        ans+=mp[make_pair(t,u)];
    }
    cout<<ans<<endl;

    
    return 0;
}
#include <iostream>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <queue>
#include <stack>
#include <algorithm>
#include <fstream>
#include <sstream>
#include <iomanip>
#define ll long long

using namespace std;

long long MOD = 1000000007;

void all_enum(string R, string B, string &S, map<string,int> &m){
    int i=(int)R.size()+B.size();
    if(i==(int)S.size()){
        string key_=R+","+B;
        //cout << key_ << endl;
        if(m.count(key_)){
            m[key_]++;
        }else{
            m[key_]=1;
        }
        return;
    }
    
    all_enum(R+S[i],B,S,m);
    all_enum(R,B+S[i],S,m);
}

ll count_pattern(string R, string B, string &T, map<string,int> &m){
    int i=(int)R.size()+B.size();
    if(i==(int)T.size()){
        string key_=R+","+B;
        //cout << key_ << endl;
        if(m.count(key_)){
            return m[key_];
        }else{
            return 0;
        }
    }

    ll cnt=0;
    cnt+=count_pattern(R+T[i],B,T,m);
    cnt+=count_pattern(R,B+T[i],T,m);
    return cnt;
}

int main(){
    int N;
    cin >> N;
    string S;
    cin >> S;
    string T=S.substr(N,N);
    reverse(T.begin(),T.end());
    S=S.substr(0,N);

    map<string,int> m;

    all_enum("","",S,m);
    //cout << "_______" << endl;
    cout << count_pattern("","",T,m) << endl;

}