#include <bits/stdc++.h>

using namespace std;

template<const size_t bufferSize>
class Scanner
{
public:

    Scanner(std::istream& s = std::cin, std::string sep = " ") : stream(s),
        buffer(new char[bufferSize]), pointer(bufferSize), lengthInput(0), separators(sep) {

        this->separators.push_back('\0');
        this->separators.push_back('\n');

        this->stream.seekg(0, this->stream.end);
        this->lengthInput = this->stream.tellg();
        this->stream.seekg(0, this->stream.beg);
    }

    Scanner(const Scanner &scan) : stream(scan.stream), pointer(scan.pointer),
        lengthInput(scan.lengthInput), separators(scan.separators) {

        for (size_t i = 0; i < bufferSize; ++i)
            this->buffer[i] = scan.buffer[i];
    }

    Scanner& operator = (const Scanner &scan)
    {
        this->stream = scan.stream;
        this->pointer = scan.pointer;
        this->lengthInput = scan.lengthInput;
        this->separators = scan.separators;

        for (size_t i = 0; i < bufferSize; ++i)
            this->buffer[i] = scan.buffer[i];

        return *this;
    }

    ~Scanner()
    {
        delete[] this->buffer;
        this->pointer = bufferSize;
        this->lengthInput = 0;
    }

    char nextChar()
    {
        if (this->eof())
            return '\0';

        if (this->pointer == bufferSize)
        {
            this->pointer = 0;
            stream.read(buffer, bufferSize);
        }

        this->lengthInput--;

        return this->buffer[this->pointer++];
    }

    size_t nextUnsigned(void)
    {
        return this->nextInteger<size_t>();
    }

    int nextInt(void)
    {
        return this->nextInteger<int>();
    }

    long long nextLongLong(void)
    {
        return this->nextInteger<long long>();
    }

    double nextDouble(void)
    {
        double key = 0;
        double fract = 0;
        int sign = 1;
        char ch;

        do
        {
            ch = this->nextChar();

        } while (separators.find(ch) != std::string::npos && ch != '+' && ch != '-' && !this->eof());

        if (!ch)
            return 0.0f;

        if (!isdigit(ch))
        {
            sign = (ch == '-') ? -1 : 1;
            ch = this->nextChar();
        }

        do
        {
            key = key * 10.0f + ch - '0';
            ch = this->nextChar();

        } while (isdigit(ch));

        if (ch == '.')
        {
            ch = this->nextChar();
            size_t lg = 0;

            do
            {
                lg++;
                fract = fract * 10.0f + ch - '0';
                ch = this->nextChar();

            } while (isdigit(ch));

            while (lg--)
                fract /= 10.0f;
        }

        return sign * (key + fract);
    }

    std::string nextString(void)
    {
        std::string str;
        char ch;

        do
        {
            ch = this->nextChar();

        } while (separators.find(ch) != std::string::npos && !this->eof());

        if (!ch)
            return str;
        do
        {
            str.push_back(ch);
            ch = this->nextChar();

        } while (separators.find(ch) == std::string::npos);

        return str;
    }

    bool eof(void) const
    {
        return this->lengthInput == 0;
    }

private:

    std::istream& stream;
    char *buffer;
    size_t pointer, lengthInput;
    std::string separators;

    template<class T>
    T nextInteger(void)
    {
        T key = 0;
        T sign = 1;
        char ch;

        do
        {
            ch = this->nextChar();

        } while (separators.find(ch) != std::string::npos && ch != '+' && ch != '-' && !this->eof());

        if (!isdigit(ch))
        {
            sign = (ch == '-') ? -1 : 1;
            ch = this->nextChar();
        }

        do
        {
            key = key * 10 + ch - '0';
            ch = this->nextChar();

        } while (isdigit(ch));

        return sign * key;
    }
};

template<const unsigned int SIGMA, const char OFFSET>
class Trie
{
private:

    class Node
    {
    public:

        int child[SIGMA];
        int parent, value;
        char numbOfChildren;

        Node() : child(), parent(), value(), numbOfChildren() {

            memset(child, 0, sizeof child);
        }
    };

    inline int alloc()
    {
        if (stack.empty() == false)
        {
            trie.push_back(Node());
            return cellPos++;
        }
        else
        {
            int t = stack.back();
            stack.pop_back();
            return t;
        }
    }

    inline void dealloc(const int pos)
    {
        stack.push_back(pos);
    }

    vector<Node> trie;
    vector<int> stack;
    int cellPos;

public:

    Trie() : trie(16), stack(16), cellPos(2) {
    }

    void insert(const string &str)
    {
        int root = 1;

        for (const char &c : str)
        {
            int kid = c - OFFSET;

            if (trie[root].child[kid] == 0)
            {
                trie[root].child[kid] = alloc();
                trie[trie[root].child[kid]].parent = root;
                trie[root].numbOfChildren++;
            }

            root = trie[root].child[kid];
        }

        trie[root].value++;
    }

    void erase(const string &str)
    {
        int root = 1;

        for (const char &c : str)
            root = trie[root].child[c - OFFSET];

        if (root != 0)
        {
            trie[root].value--;
            size_t i = str.size();

            while (trie[root].value == 0 && !trie[root].numbOfChildren && (root != 1))
            {
                i--;
                dealloc(root);
                root = trie[root].parent;
                trie[root].child[str[i] - OFFSET] = 0;
                trie[root].numbOfChildren--;
            }
        }
    }

    int count(const string &str) const
    {
        int root = 1;
        size_t i = 0;

        while (i < str.size() && trie[root].child[str[i] - OFFSET])
        {
            root = trie[root].child[str[i] - OFFSET];
            i++;
        }

        if (root != 0)
            return trie[root].value;
        else
            return 0;
    }

    int prefixMatch(const string &str) const
    {
        int root = 1;
        size_t i = 0;

        while (i < str.size() && trie[root].child[str[i] - OFFSET])
        {
            root = trie[root].child[str[i] - OFFSET];
            i++;
        }

        return static_cast<int>(i);
    }
};

int main()
{
    ifstream in("trie.in");
    ofstream out("trie.out");

    Trie<26, 'a'> T;

    int t;
    string s;

    while (in >> t >> s)
    {
        if (t == 0)
            T.insert(s);
        else if (t == 1)
            T.erase(s);
        else if (t == 2)
            out << T.count(s) << "\n";
        else
            out << T.prefixMatch(s) << "\n";
    }

    return 0;
}