#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
#define fst first
#define snd second
#define pb push_back
const int maxn = 4e5;
int L;
typedef pair<ll, ll> Pll;
const ll b1 = 61;
const ll b2 = 67;
const ll p1 = 1e9 + 7;
const ll p2 = p1 + 2;
Pll dodaj_char(char c, Pll x)
{
	ll val = c - 'a' + 1;
	x.fst = (x.fst * b1 + val) % p1;
	x.snd = (x.snd * b2 + val) % p2;
	return x;
}
Pll operator-(Pll lhs, Pll rhs)
{
	lhs.fst -= rhs.fst;
	if(lhs.fst < 0)
		lhs.fst += p1;
	lhs.snd -= rhs.snd;
	if(lhs.snd < 0)
		lhs.snd += p2;
	return lhs;
}
ll B1[maxn];
ll B2[maxn];
Pll przesuj(int val, Pll x)
{
	return {x.fst * B1[val] % p1, x.snd * B2[val] % p2};
}
Pll H[maxn];
char buff[maxn];
char A[maxn];
set<Pll> Dost[maxn];
vi vdost;
int wynik[maxn];
struct Tree
{
	
	vi V;
	int d;
	Tree(int x)
	{
		d = 1;
		while(d <= x)
			d *= 2;
		V.assign(2*d, 1000000000);
	}
	void add(int x, int pos)
	{
		pos += d;
		V[pos] = x;
		pos /= 2;
		while(pos != 0)
		{
			V[pos] = min(V[2*pos + 1], V[2 * pos]);
			pos /= 2;
		}
	}
	int query(int a, int b)
	{
		a += d;
		b += d;
		int res = min(V[a], V[b]);
		
		
		while(a / 2 != b / 2)
		{
			if((a & 1) == 0)
				res = min(res, V[a+1]);
			if((b & 1) != 0)
				res = min(res, V[b-1]);
			a /= 2;
			b /= 2;
		}
		return res;
	}
};
int main()
{
	scanf("%d", &L);
	scanf("%s", A);
	
	int len = strlen(A);
	B1[0] = B2[0] = 1;
	for(int i = 1; i <= len; ++i)
	{
		B1[i] = B1[i-1] * b1 % p1;
		B2[i] = B2[i-1] * b2 % p2;
	}
	for(int i = len - 1; i >= 0; --i)
	{
		H[i] = dodaj_char(A[i], H[i+1]);
	}
	set<int> pom;
	for(int i = 0; i < L; ++i)
	{
		scanf("%s", buff);
		Pll res(0,0);
		int l2 = strlen(buff);
		pom.insert(l2);
		for(int j = l2-1; j >= 0; --j)
		{
			res = dodaj_char(buff[j], res);
		}
		Dost[l2].insert(res);
	}
	vdost = vi(pom.rbegin(), pom.rend());
	Tree t(len+10);
	t.add(0,0);
	for(int i = 0; i < len; ++i)
	{
		for(int v : vdost)
		{
			if(i - v + 1 >= 0)
			{
				Pll hasz = H[i-v + 1] - przesuj(v, H[i+1]);
				if(Dost[v].count(hasz))
				{
					//puts("TRAFIONY");
					int res = t.query(i-v + 1, i);
					//printf("res = %d\n", res);
					t.add(res + 1, i+1);
					break;
				}
			}
			
		}
		
	}
	int r = t.query(len, len);
	if(r > 10000000)
		r = -1;

	printf("%d\n", r);
	
}