#include<iostream>
using namespace std;
string s[42], str, res;
bool vis[42];
int n;
char head;
int longest;
int check(string s1, string s2) {
	for (int i = s1.size() - 1; i >= 0; i--) {
		if(s1.substr(i)==s2.substr(0,s1.size()-i))
			return s1.size() - i;
	}
	return -1;
}
void dfs(string ans, int dep) {
	if (ans.size() > longest) {
		longest = ans.size();
		res = ans;
	}
	if (dep == 2 * n + 1)return;
	for (int i = 1; i <= 2 * n; i++) {
		if (dep == 1 && s[i][0] == head && !vis[i]) {
			vis[i] = 1;
			dfs(ans + s[i], dep + 1);
			vis[i] = 0;
		}
		else if (dep >= 2&&!vis[i]) {
			int pos=check(ans, s[i]);
			if (pos != -1) {
				vis[i] = 1;
				dfs(ans + s[i].substr(pos), dep + 1);
				vis[i] = 0;
			}
		}
	}
}
int main()
{
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> s[i];
	for (int i = n + 1; i <= 2 * n; i++) s[i] = s[i - n];
	cin >> head;
	dfs(str, 1);
	cout<< longest << endl;
	return 0;
}