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

#define REP(i,a,b) for (int i = (a); i <= (b); ++i)
#define FOR(i,n) REP(i,0,int(n)-1)
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define vi vector<int>
#define SZ(x) int((x).size())
#define FOREACH(i,t) for (auto i = t.begin(); i != t.end(); ++i)
#define fi first
#define se second

struct node
{
    node *son[26], *cache[26];
    //int cnt;
    //map < char, node* > son, cache;
    node *lnk, *wo;
    int el;
    node () : el(-1) {}
};

const int N = 3e5 + 7, INF = 1e9;
vi len;
node root;
set < string > S;
vector < int > D;
vector < int > A[N];
int DP[N];

node* mv (node *w, int l)
{
    node*& r = w->cache[l];
    return r ? r : r = ((w->son[l] != nullptr) ? w->son[l] : w == &root ? w : mv(w->lnk, l));
}

int addWord (const char *s)
{
    int l = strlen(s);
    node *p = &root;
    for (; *s; ++s)
    {
        int letter = (int)(*s - 'a');
        auto e = p->son[letter];
        p = (e == nullptr) ? p->son[letter] = new node : e;
    }
    if (p->el == -1) { p->el = SZ(len); len.pb(l); }
    return p->el;
}

void calcLink ()
{
    vector < node* > l;
    node *w;
    root.lnk = root.wo = 0;

    for (int i = 0; i < 26; ++i)
    {
        if (root.son[i] == nullptr)
            continue;
        auto it = root.son[i];
        l.pb(it); it->lnk = &root;
    }
    //FOREACH(it,root.son) { l.pb(it->se); it->se->lnk = &root; }
    FOR(x,SZ(l))
    {
        l[x]->wo = (l[x]->lnk->el != -1) ? l[x]->lnk : l[x]->lnk->wo;
        for (int i = 0; i < 26; ++i)
        {
            if (l[x]->son[i] == nullptr)
                continue;
            auto it = l[x]->son[i];
            l.pb(it); w = l[x]->lnk; w = mv(w, i); it->lnk = w;
        }
    }
}

vector < pii > searchAll (const char *s)
{
    vector < pii > ans;
    node *p = &root, *r;
    for (int x = 0; s[x]; ++x)
    {
        int letter = (int)(s[x] - 'a');
        p = mv(p, letter);
        for (r = p; r; r = r->wo) if (r->el != -1) ans.pb(mp(x - len[r->el] + 1, r->el));
    }
    return ans;
}

int main ()
{
    ios_base::sync_with_stdio(false);

    int n;
    string text;
    cin >> n >> text;

    string s;
    for (int i = 0; i < n; ++i)
    {
        cin >> s;
        if (S.find(s) == S.end())
        {
            S.insert(s);
            D.push_back(s.size());
            auto sstr = s.c_str();
            addWord(sstr);
        }
    }

    calcLink();

    vector < pii > ans = searchAll(text.c_str());

    for (int i = 0; i < ans.size(); ++i)
        A[ans[i].fi].push_back(D[ans[i].se]);
        //printf("%d %d\n", ans[i].fi, ans[i].se);

    int maxi = -1;

    for (auto d : A[0])
        maxi = max(maxi, d);

    if (maxi == -1)
    {
        cout << "-1";
        return 0;
    }

    int it = 1, result = 1;
    while (true)
    {
        if (maxi == text.size())
            break;

        int nMaxi = -1;
        while (it <= maxi)
        {
            for (auto d : A[it])
                nMaxi = max(nMaxi, it + d);
            ++it;
        }

        if (nMaxi == -1)
            break;

        ++result;
        maxi = nMaxi;
    }

    if (maxi < text.size())
        cout << "-1";
    else
        cout << result;

    return 0;
}