#include<fstream>
#include<iostream>
#include<string>
#define SIGMA 26
using namespace std;

class TrieNode {
private:
    TrieNode* next[SIGMA];
    int cnt;
public:
    TrieNode() {
        this->cnt = 0;
        for(int i = 0; i < SIGMA; ++i)
            this->next[i] = NULL;
    }
    void insertWord(string&, unsigned);
    bool deleteWord(string&, unsigned);
    unsigned searchWord(string&, unsigned);
    unsigned prefixSearch(string&, unsigned);
};

void TrieNode::insertWord(string& word, unsigned pos) {
    if(pos == word.size())
        this->cnt++;
    else {
        if(this->next[word[pos] - 'a'] == NULL)
            this->next[word[pos] - 'a'] = new TrieNode;
        this->next[word[pos] - 'a']->insertWord(word, pos + 1);
    }
}

bool TrieNode::deleteWord(string& word, unsigned pos) {
    if(pos == word.size()) {
        if(this->cnt == 0)
            return false;
        else {
            this->cnt--;
            return true;
        }
    } else {
        if(this->next[word[pos] - 'a'] == NULL)
            return false;
        else {
            bool ans = this->next[word[pos] - 'a']->deleteWord(word, pos + 1);
            if(ans) {
                TrieNode* son = this->next[word[pos] - 'a'];
                bool toDelete = son->cnt == 0;
                for(int i = 0; i < SIGMA; ++i)
                    toDelete &= son->next[i] == NULL;
                if(toDelete) {
                    delete son;
                    this->next[word[pos] - 'a'] = NULL;
                }
            }
        }
    }
}

unsigned TrieNode::searchWord(string& word, unsigned pos) {
    if(pos == word.size())
        return this->cnt;
    else {
        if(this->next[word[pos] - 'a'] == NULL)
            return 0;
        else return this->next[word[pos] - 'a']->searchWord(word, pos + 1);
    }
}

unsigned TrieNode::prefixSearch(string& word, unsigned pos) {
    if(pos == word.size() || this->next[word[pos] - 'a'] == NULL)
        return pos;
    else return this->next[word[pos] - 'a']->prefixSearch(word, pos + 1);
}

TrieNode* root;

int main() {
    ifstream fin("trie.in");
    ofstream fout("trie.out");
    string s;
    int op;
    root = new TrieNode;
    fin >> op >> s;
    while(!fin.eof()) {
        if(op == 0)
            root->insertWord(s, 0);
        else if(op == 1) {
            root->deleteWord(s, 0);
        } else if(op == 2)
            fout << root->searchWord(s, 0) << '\n';
        else fout << root->prefixSearch(s, 0) << '\n';
        fin >> op >> s;
    }
    fin.close();
    fout.close();
    return 0;
}