#include <bits/stdc++.h>

using namespace std;

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

struct Trie
{
    int pre, nr, sons[30];
}v[45005];

string s;
int k;

void insertWord(string s)
{
    int nod = 0;
    for (int i = 0; i < s.size(); ++i)
    {
        int next = v[nod].sons[s[i] - 'a'];
        if (next == 0)
            v[nod].sons[s[i] - 'a'] = ++k;
        nod = v[nod].sons[s[i] - 'a'];
        v[nod].pre++;
    }
    v[nod].nr++;
}

void deleteWord(string s)
{
    int nod = 0;
    for (int i = 0; i < s.size(); ++i)
    {
        int next = v[nod].sons[s[i] - 'a'];
        nod = next;
        v[nod].pre--;
    }
    v[nod].nr--;
}

int cateCuvinte(string s)
{
    int nod = 0;
    for (int i = 0; i < s.size(); ++i)
    {
        int next = v[nod].sons[s[i] - 'a'];
        if (next == 0)
            return 0;
        nod = next;
    }
    return v[nod].nr;
}

int prefix(string s)
{
    int nod = 0;
    for (int i = 0; i < s.size(); ++i)
    {
        int next = v[nod].sons[s[i] - 'a'];
        nod = next;
        if (v[nod].pre <= 0)
            return i;
    }
    return s.size();
}

int main()
{
    int p;
    while (in >> p)
    {
        in >> s;
        if (p == 0)
            insertWord(s);
        else if (p == 1)
            deleteWord(s);
        else if (p == 2)
            out << cateCuvinte(s) << '\n';
        else
            out << prefix(s) << '\n';
    }
    return 0;
}