#include <bits/stdc++.h>
#define Nmax 2000002
#define Lmax 22

FILE *fin  = freopen("trie.in", "r", stdin);
FILE *fout = freopen("trie.out", "w", stdout);

using namespace std;
int N;
struct nod
{
    char ch;
    int s, b;
    int ap, aw;
} T[Nmax];
void insert_w(int node, char *word)
{
    int bro, j;
    if(*word == 0)
    {
        ++ T[node].aw;
        return;
    }

    for(j = T[node].s; j; j = T[j].b)
        if(T[j].ch == *word)
        {
            ++ T[j].ap;
            node = j;
            break;
        }
        else bro = j;
    if(j == 0)
    {
        T[N += 1].ch = *word;
        T[N].ap = 1;
        if(!T[node].s)
            T[node].s = N;
        else T[bro].b = N;
        node = N;
    }
    insert_w(node, word + 1);
}
void erase_w(int node, char *word)
{
    int j;
    if(*word == 0)
    {
        -- T[node].aw;
        return;
    }

    for(j = T[node].s; j; j = T[j].b)
        if(T[j].ch == *word)
        {
            if(T[j].ap > 0)
                -- T[j].ap;
            node = j;
            break;
        }
    erase_w(node, word + 1);
}
int appearance(int node, char *word)
{
    bool f = 0;
    if(*word == 0)
        return T[node].aw;

    for(int j = T[node].s; j; j = T[j].b)
        if(T[j].ch == *word)
        {
            f = 1;
            node = j;
            break;
        }
    if(!f)
        return 0;
    else
        appearance(node, word + 1);
}

int lenght_prefix(int node, char *word, int depth)
{
    bool f = 0;
    if(*word == 0)
        return depth;

    for(int j = T[node].s; j; j = T[j].b)
        if(T[j].ch == *word && T[j].ap > 0)
        {
            f = 1;
            node = j;
            break;
        }
    if(!f)
        return depth;
    else lenght_prefix(node, word + 1, depth + 1);
}
int main()
{
    int c;
    char word[Lmax];
    while(scanf("%d ", &c) != EOF)
    {
        gets(word);
        if(c == 0) insert_w(0, word);
        if(c == 1) erase_w(0, word);
        if(c == 2) printf("%d\n", appearance(0, word));
        if(c == 3) printf("%d\n", lenght_prefix(0, word, 0));
    }
    return 0;
}