#include <iostream>
#include <fstream>
#include <cstring>
#include <cstdio>
using namespace std;


struct Node {
        int npassing;
        int nwords;
        Node* children[26];
        Node() {
                npassing = nwords = 0;
                memset(children, 0, sizeof(children));
        }
};


void add(Node* node, char word[]) {
        if (strlen(word) == 0)
                return;
        if (node->children[word[0] - 'a'] == 0)
                node->children[word[0] - 'a'] = new Node;
        node->children[word[0] - 'a']->npassing++;
        
        if (strlen(word) == 1) 
                node->children[word[0] - 'a']->nwords++;
        else
                add(node->children[word[0] - 'a'], word + 1);
}


void delete_app(Node* node, char word[]) {
        if (strlen(word) != 1)
                delete_app(node->children[word[0] - 'a'], word + 1);
        else
                node->children[word[0] - 'a']->nwords--;
        node->children[word[0] - 'a']->npassing--;
        if(node->children[word[0] - 'a']->npassing == 0) {
                delete node->children[word[0] - 'a'];
                node->children[word[0] - 'a'] = 0;
        }
}


int number_app(Node* node, char word[]) {
        if (strlen(word) == 0 || node->children[word[0] - 'a'] == 0)
                return 0;
        if (strlen(word) == 1)
                return node->children[word[0] - 'a']->nwords;
        return number_app(node->children[word[0] - 'a'], word + 1);
}


int largest_prefix(Node* node, char word[]) {
        if (strlen(word) == 0 || node->children[word[0] - 'a'] == 0)
                return 0;
        return 1 + largest_prefix(node->children[word[0] - 'a'], word + 1);
}


int main() {
        int type;
        char word[20];
        Node* root = new Node;
        ifstream fin("trie.in");
        ofstream fout("trie.out");
        while (fin >> type >> word) {
                switch (type) {
                        case 0:
                                add(root, word);
                                break;
                        case 1:
                                delete_app(root, word);
                                break;
                        case 2:
                                fout << number_app(root, word) << '\n';
                                break;
                        case 3:
                                fout << largest_prefix(root, word) << '\n';
                                break;
                }
        }
        return 0;
}