#include <bits/stdc++.h>
using namespace std;

int n;
long long ans;
string a,z;
map<pair<string,string>,int> M;

void dfs(int i,int j,string x,string y)
{
	if(i>j)
	{
		z="";
		for(int i=x.size()-1;i>=0;i--)z+=x[i];
		x=z,z="";
		for(int i=y.size()-1;i>=0;i--)z+=y[i];
		y=z;
		M[make_pair(x,y)]++;
		return ;
	}
	dfs(i+1,j,x+a[i],y);
	dfs(i+1,j,x,y+a[i]);
}

void dfs2(int i,int j,string x,string y)
{
	if(i>j)
	{
		ans+=M[make_pair(x,y)];
		return ;
	}
	dfs2(i+1,j,x+a[i],y);
	dfs2(i+1,j,x,y+a[i]);
}

int main()
{
	cin>>n>>a;
	dfs(0,n-1,"","");
	dfs2(n,n*2-1,"","");
	cout<<ans;
	return 0;
}
