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

class Trie {
private:    
    struct Node{
        int count;
        Node* next[26];
        Node* father;
        
        Node(Node* father_ = nullptr): count(0), father(father_) {
            for (int i=0; i<26; i++)
                next[i] = nullptr;
        }
        ~Node(){
            count = 0;
            for (int i=0; i<26; i++)
                next[i] = nullptr;
            father = nullptr;
        }
    } *root;
    
    bool is_deleteable(Node* node){
        bool flag = (node->count > 0);
        for (int i=0; i<26; i++){
            flag |= (node->next[i] != nullptr);
        }
            
        return !flag;
    }   
    
    
public:

    Trie(): root(new Node()) {}
    
    void insert(string word) {
        Node* current_node = root;
        unsigned i = 0;
        while (i < word.size()){
            if (current_node->next[word[i] - 'a'] == NULL){
                current_node->next[word[i] - 'a'] = new Node(current_node);
            }
            current_node = current_node->next[word[i] - 'a'];
            i++;
        }
        current_node->count++;
    }
    
    void erase(string word){
        Node* current_node = root;
        unsigned i = 0;
        while (i < word.size()){
            current_node = current_node->next[word[i] - 'a'];
            i++;
        }
        current_node->count--;
        while (is_deleteable(current_node)){
            Node* aux = current_node->father;
            for (i=0; i<26; i++){
                if (aux->next[i] == current_node)
                    aux->next[i] = nullptr;
            }
            delete current_node;
            current_node = aux;
        }
    }
    
    int count_appearences(string word) {
        Node * current_node = root;
        unsigned i = 0;
        while (i < word.size()){
            if (!current_node->next[word[i] - 'a'])
                return 0;
            current_node = current_node->next[word[i] - 'a'];
            i++;
        }
        return current_node->count;
    }
    
    int lcs(string word){
        Node * current_node = root;
        unsigned i = 0;
        while (i < word.size()){
            if (current_node->next[word[i] - 'a'] == nullptr)
                break;
            current_node = current_node->next[word[i] - 'a'];
            i++;
        }
        return i;
    }
};

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    ifstream cin ("trie.in");
    ofstream cout ("trie.out");
    Trie t;
    int o; string s;
    while (cin >> o >> s){
        if (o == 0) t.insert(s);
        else if (o == 1) t.erase(s);
        else if (o == 2) cout << t.count_appearences(s) << '\n';
        else cout << t.lcs(s) << '\n';
    }
    return 0;
}