#include <fstream>
using namespace std;

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

struct Trie {
    int countSons;
    int countWords;
    Trie *actualSon[26];
    Trie()
    {
        countSons = 0;
        countWords = 0;
        for ( int i = 0; i < 26; ++i )
            actualSon[i] = 0;
    }
}; Trie *T = new Trie;

void addWord(Trie *x, char *s );
bool deleteWord(Trie *x, char *s);
void countApparitions(Trie *x, char *s);
int preffixLength(Trie *x, char *s, int length);

int Q, type, NrAP;
char A[21];

int main()
{
    while ( is >> type)
    {
        is >> A;
        switch(type)
        {
        case 0:
            addWord(T,A);
            break;
        case 1:
            deleteWord(T,A);
            break;
        case 2:
            NrAP = 0;
            countApparitions(T,A);
            os << NrAP << '\n';
            break;
        case 3:
            os << preffixLength(T,A,0) << '\n';
            break;
        }
    }

    is.close();
    os.close();
}

void addWord(Trie *x, char *s)
{
    if ( s[0] == NULL )
    {
        x->countWords++;
        return;
    }
    if ( x->actualSon[s[0] - 'a'] == 0 )
    {
        x->countSons++;
        x->actualSon[s[0] - 'a'] = new Trie;
    }
    addWord(x->actualSon[s[0] - 'a'], s + 1);
}

bool deleteWord(Trie *x, char *s)
{
    if ( s[0] == NULL )
       x->countWords--;

    if ( s[0] != NULL )
    {
        if ( deleteWord(x->actualSon[s[0] - 'a'], s + 1 ) )
        {
            x->countSons--;
            x->actualSon[s[0] - 'a'] = 0;
        }
    }

    if ( x->countWords == 0 && x->countSons == 0 && x != T )
    {
        delete x;
        return 1;
    }
    else
        return 0;
}

void countApparitions(Trie *x, char *s)
{
    if ( s[0] == NULL )
    {
        NrAP += x->countWords;
        return;
    }
    else
    {
        if ( x->actualSon[s[0] - 'a'] != 0)
        countApparitions(x->actualSon[s[0] - 'a'],s + 1);
    }
}

int preffixLength(Trie *x, char *s,int length)
{
    if ( s[0] == NULL || x->actualSon[s[0] - 'a'] == 0 )
        return length;
    else
        return preffixLength(x->actualSon[s[0] - 'a'], s + 1, length + 1);
}