#include <vector>
#include <map>
#include <iostream>
#include <queue>
#include <cassert>
using namespace std;

const int MAXN = 1e6+42;
map<char, int> to[MAXN];
int link[MAXN], que[MAXN];
int sz = 1;
int max_l[MAXN];


void add_str(string const& s)
{
	int v = 0;
	for(auto c : s)
	{
			if(!to[v][c]) to[v][c] = sz++;
			v = to[v][c];
	}
	max_l[v] = max((int)max_l[v], (int)s.size());
}

void push_links()
{
	link[0] = -1;
	int st = 0, fi = 1;
	que[0] = 0;
	while(st < fi) { int v= que[st++];
		
		//cerr << v <<" " << link[v] << endl;
		if(link[v] != -1)
			max_l[v] = max(max_l[v], max_l[link[v]]);
		for(auto it : to[v])
		{
			int u = it.second;
			int c = it.first;
			int j = link[v];
			while(j!=-1 && !to[j][c]) j = link[j];
			if(j!=-1)	 link[u] = to[j][c];
				else link[u] = 0;
			que[fi++] = u;
		}
	}
	//cerr << "A " << fi << endl;
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n; cin >> n;
	string s; cin >> s;
	//assert(n == s.size());
	for(int i=0; i<n; i++)
	{
		string tmp; cin >> tmp; add_str(tmp);
	}
	push_links();
	
	//for(int i=0; i<sz; i++)
	//	cout << max_l[i] << " ";
	//cout << endl;
	
	int M = s.size();
	vector<vector<pair<int, int> > > edges;
	edges.resize(M+1);
	int j=0;
	for (int i=0; i < M; i ++) {
		while (j != -1 && !to[j][s[i]]) j = link[j]; 
		if (j==-1) j=0;
		else j=to[j][s[i]];
		edges[i+1].push_back(make_pair(i, 0));
		//cout << "max_l " << j << " " << max_l[j] << endl;
		if (max_l[j] == 0) continue;
		int start = i - max_l[j] + 1;
		edges[start].push_back(make_pair(i+1, 1));
		//cout << "add edge " << start << " " << i +1 << endl;
	}
	
	vector<int> dist;
	dist.resize(M+1, -1);
	priority_queue<pair<int, int> > que;
	que.push(make_pair(0, 0));
	dist[0]=0;
	
	while (que.size() > 0) {
		auto node1 = que.top();
		
		que.pop();
		int node = node1.second;
		//cout << "node " << node << endl;
		
		if (dist[node] != -node1.first) continue;
		
		for (auto ed : edges[node]) {
			int child = ed.first;
			int cost = ed.second;
			int newcost = cost + dist[node];
			if (dist[child]==-1 || newcost < dist[child]) {
				dist[child]=newcost;
				que.push(make_pair(-newcost, child));
			}
		}
	}
	cout << dist[M] << endl;
}