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

using namespace std;

class Trie {
    struct Node {
        int cnt = 0, lvs = 0;
        int next[26] = {};
    };
    vector<Node> trie;

public:
    inline Trie() noexcept 
        : trie(1) {}

    inline void insert(const string& str) {
        int node = 0;
        for (const char chr : str) {
            if (trie[node].next[chr - 'a'] == 0) {
                trie[node].next[chr - 'a'] = trie.size();
                trie.emplace_back();
            }
            node = trie[node].next[chr - 'a'];
            ++trie[node].lvs;
        }
        ++trie[node].cnt;
    }

    inline void erase(const string& str) {
        int node = 0;
        for (const char chr : str) {
            node = trie[node].next[chr - 'a'];
            --trie[node].lvs;
        }
        --trie[node].cnt;
        node = 0;
        for (const char chr : str) {
            if (trie[trie[node].next[chr - 'a']].lvs == 0) {
                trie[node].next[chr - 'a'] = 0;
                return;
            }
            node = trie[node].next[chr - 'a'];
        }
    }

    inline int count(const string& str) {
        int node = 0;
        for (const char chr : str) {
            if (trie[node].next[chr - 'a'] == 0)
                return 0;
            node = trie[node].next[chr - 'a'];
        }
        return trie[node].cnt;
    }

    inline int lcp(const string& str) {
        int node = 0, len = 0;
        for (const char chr : str) {
            if (trie[node].next[chr - 'a'] == 0)
                return len;
            node = trie[node].next[chr - 'a'];
            ++len;
        }
        return len;
    }
};

ifstream fin("trie.in");
ofstream fout("trie.out");

int main() {
    Trie trie;

    int task;
    string str;
    while (fin >> task >> str) {
        if (task == 0) trie.insert(str);
        else if (task == 1) trie.erase(str);
        else if (task == 2) fout << trie.count(str) << '\n';
        else fout << trie.lcp(str) << '\n';
    }

    fin.close();
    fout.close();
    return 0;
}