#include <bits/stdc++.h>
using namespace std;
void DAU(const string &task = "") {
    if (!task.empty())
        freopen((task + ".in").c_str(), "r", stdin),
        freopen((task + ".out").c_str(), "w", stdout);
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}
void PLEC() {
    exit(0);
}
const int SIGMA(26);
class Trie {
public:
    Trie() : cntsons(0), freq(0) {
        memset(sons, 0, sizeof(sons));
    }
    inline void Query(const int& op, const string& s) {
        if (op == 0)
            Add(s);
        else if (op == 1)
            Erase(s);
        else if (op == 2)
            cout << Count(s) << '\n';
        else if (op == 3)
            cout << LongestPref(s) << '\n';
    }
private:
    inline void Add(const string& s, const size_t& ind = 0) {
        int x = s[ind] - 'a';
        if (!sons[x]) {
            ++cntsons;
            sons[x] = new Trie;
        }
        if (ind == s.size() - 1)
            ++sons[x] -> freq;
        else sons[x] -> Add(s, ind + 1);
    }
    inline void Erase(const string& s, const size_t& ind = 0) {
        int x = s[ind] - 'a';
        if (ind == s.size() - 1)
            --sons[x] -> freq;
        else sons[x] -> Erase(s, ind + 1);
        if (sons[x] -> cntsons + sons[x] -> freq == 0) {
            delete sons[x];
            sons[x] = 0;
            --cntsons;
        }
    }
    inline int Count(const string& s, const size_t& ind = 0) const {
        int x = s[ind] - 'a';
        if (sons[x]) {
            if (ind == s.size() - 1)
                return sons[x] -> freq;
            return sons[x] -> Count(s, ind + 1);
        }
        return 0;
    }
    inline int LongestPref(const string& s, const size_t& ind = 0) const {
        int x = s[ind] - 'a';
        if (sons[x] && ind < s.size())
            return sons[x] -> LongestPref(s, ind + 1);
        return ind;
    }
    int cntsons, freq;
    Trie *sons[SIGMA];
};
Trie *root = new Trie;
int op;
string s;
signed main() {
    DAU("trie");
    while (cin >> op >> s)
        root -> Query(op, s);
    PLEC();
}