#include <fstream>
#include <vector>
#include <string>

using namespace std;

ifstream cin("trie.in");
ofstream cout("trie.out");
  
struct node {

  node() {
    full_frecv = 0;
    part_frecv = 0;
    next_trie.resize(26);
    for (auto &x : next_trie) {
      x = NULL;
    }
  }

  int full_frecv;
  int part_frecv;
  vector < node* > next_trie;
};

class Trie {
public:
  Trie() {
    _base_trie = new node;
  }

  void Solve(string s, int type) {
    
    if (type == 0) {
      _op_01(s, 1);
    }
    else if (type == 1) {
      _op_01(s, -1);
    }
    else if (type == 2) {
      _op_2(s);
    }
    else {
      _op_3(s);
    }
  }

private:
  node* _base_trie;
  node* _cur_trie;

  void _op_01(string s, int type) {

    _cur_trie = _base_trie;
    for (auto x : s) {
      int index = x - 'a';
      if (not _cur_trie -> next_trie[index]) {  
        _cur_trie -> next_trie[index] = new node(); 
      }

      _cur_trie = _cur_trie -> next_trie[index];
      _cur_trie -> part_frecv += type;
    }

    _cur_trie -> full_frecv += type;
  }

  void _op_2(string s) {

    _cur_trie = _base_trie;
    for (auto x : s) {
      int index = x - 'a';
      if (not _cur_trie -> next_trie[index]) {
        cout << 0 << '\n';
        return;
      }
      _cur_trie = _cur_trie -> next_trie[index];
    }

    cout << _cur_trie -> full_frecv << '\n';
  }

  void _op_3(string s) {

    int cnt = 0;
    _cur_trie = _base_trie;
    for (auto x : s) {
      if (not _cur_trie -> next_trie[x - 'a']) {
        break;
      }

      _cur_trie = _cur_trie -> next_trie[x - 'a'];
      if (not _cur_trie -> part_frecv) {
        break;
      }
      cnt ++;
    }

    cout << cnt << '\n';
  }
};

int main(int argc, char const *argv[]) {
  
  int type;
  string s;
  Trie* T = new Trie();

  while (cin >> type) {

    cin >> s;
    T -> Solve(s, type);
  }
}