#include <cstdio>
#include <queue>
#include <algorithm>
#include <cstring>

using namespace std;

typedef long long llint;
typedef pair<int, int> pii;

const int MAX = 3 * (1 << 17);
const int ALPHA = 26;

int V;
int trie[MAX][ALPHA];
int fn[MAX];
int sn[MAX];
int length[MAX];

int node() {
  for (int i = 0; i < ALPHA; ++i) trie[V][i] = 0;
  fn[V] = 0;
  sn[V] = 0;
  length[V] = 0;
  return V++;
}

int insert(char *s) {
  int t = 0;
  int len = 0;
  for (; *s; ++s) {
    int c = *s - 'a';
    if (trie[t][c] == 0) trie[t][c] = node();
    t = trie[t][c];
    ++len;
  }
  length[t] = len;
  return t;
}

void init_aho() {
  queue<int> Q;
  Q.push(0);

  while (!Q.empty()) {
    int t = Q.front(); Q.pop();
    for (int c = 0; c < ALPHA; ++c) {
      int x = trie[t][c];
      if (x) {
        Q.push(x);

        if (t) {
          fn[x] = fn[t];
          while (fn[x] && trie[fn[x]][c] == 0) fn[x] = fn[fn[x]];
          if (trie[fn[x]][c]) fn[x] = trie[fn[x]][c];
          if (length[fn[x]]) {
            sn[x] = fn[x];
          } else {
            sn[x] = sn[fn[x]];
          }
        }

      }
    }
  }
}

int l;
char word[MAX];
char buff[MAX];
int sol[MAX];

void init_sol() {
  int t = 0;
  memset(sol, -1, sizeof sol);
  for (int i = 0; word[i]; ++i) {
    int c = word[i] - 'a';
    while (t && trie[t][c] == 0) t = fn[t];
    if (trie[t][c]) {
      t = trie[t][c];
      int last = t;
      while (last) {
        if (length[last]) {
          sol[i - length[last] + 1] = max(sol[i - length[last] + 1], i);
        }
        last = sn[last];
      }
    }
  }
}

int solve() {
  for (int i = 1; word[i]; ++i) {
    sol[i] = max(sol[i-1], sol[i]);
  }

  int last = 0;
  int ans = 0;
  while (word[last+1]) {
    ++ans;
    int next = sol[last+1];
    if (next <= last) return -1;
    last = next;
  }
  return ans;
}

int main(void) {
  scanf("%d", &l);

  scanf("%s", word);

  for (int i = 0; i < l; ++i) {
    scanf("%s", buff);
    insert(buff);
  }

  init_aho();
  init_sol();

  printf("%d\n", solve());

  return 0;
}