#include <bits/stdc++.h>

using namespace std;

const int N = 3e5 + 7;
const int SIGMA = 26;
const char OFFSET = 'a';

int n;
string text;

int OK[N];
int F[N], l[N];
int V = 0, G[N][SIGMA];

void insert(const string &s){
	int v = 0;
	for(char c: s){
		c -= OFFSET;
		if(G[v][c] == 0) G[v][c] = ++V;
		v = G[v][c];
	}
	
	OK[v] = s.size();
}

void init(){
	queue <int> Q;
	Q.push(0);
	
	while(!Q.empty()){
		int v = Q.front();
		Q.pop();
		
		for(int c = 0; c < SIGMA; ++c){
			int w = G[v][c];
			if(w == 0)	continue;
			Q.push(w);
			if(v == 0)	continue;
			F[w] = F[v];
			while(F[w] && G[F[w]][c] == 0) F[w] = F[F[w]];
			if(G[F[w]][c]) F[w] = G[F[w]][c];
		}
		
		for(int c = 0; c < SIGMA; ++c)
			if(G[v][c] == 0)
				G[v][c] = G[F[v]][c];
		OK[v] = max(OK[v], OK[F[v]]);
	}
}

int main(){
	cin >> n;
	cin >> text;
	
	for(int i = 0; i < n; ++i){
		string cur;
		cin >> cur;
		insert(cur);
	}
	
	init();
	int cur = 0;
	
	for(int i = 0; i < text.size(); ++i){
		cur = G[cur][text[i] - OFFSET];
		l[i] = OK[cur];
	}
	
	int last = text.size() - 1, last2 = text.size() - 1, res = 0;
	for(int i = text.size() - 1; i >= 0; --i){
		if(i < last){
			if(i < last2){
				puts("-1");
				exit(0);
			}
			
			last = last2;
			++res;
		}
		
		last2 = min(last2, i - l[i]);
	}
	
	if(last == 0){
		if(last2 < 0)
			++res;
		else{
			puts("-1");
			return 0;
		}
	}
	
	printf("%d\n", res);
	return 0;
}