#include<iostream>
#include<fstream>
#include<cstring>
using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
struct trie{
    trie *t[26] = {};
    int cnt[26];
    int total_cnt;
    bool end_of_w;
    trie()
    {
        end_of_w = false;
        total_cnt = 0;
    }
};
trie *t_node;
int convert_char_to_int(char c)
{
    return int(c)-97;
}
void add_w(char *w)
{
    int i=0;
    trie *it = t_node;
    while(i < strlen(w))
    {
        int poz = convert_char_to_int(w[i]);
        if(it->t[poz] == NULL)
        {
            it->t[poz] = new trie;
        }
        it->cnt[poz]++;
        it->total_cnt++;
        it = it->t[poz];
        i++;
    }
    it->end_of_w = true;
}
void delete_w(char *w,int i,trie*& it)
{
    int poz = convert_char_to_int(w[i]);
    trie *next_it = it->t[poz];
    it->cnt[poz]--;
    if(i+1 < strlen(w))  delete_w(w,i+1,next_it);
    if(i == strlen(w)-1) it->t[poz]->end_of_w = false;
    if(it->t[poz]->total_cnt == 0)
    {
        it->total_cnt--;
        delete it->t[poz];
        it->t[poz] = NULL;
    }
}
int query_word(char *w,int i,trie* it)
{
    int poz = convert_char_to_int(w[i]);
    if(i == strlen(w)-1)
    {
        if(it->t[poz] != NULL)
        {
            if(it->t[poz]->end_of_w == true) return it->cnt[poz];
            else return 0;
        }
        else return 0;
    }
    if(it->t[poz] != NULL)
    {
        if(i+1 < strlen(w)) query_word(w,i+1,it->t[poz]);
    }
    else return 0;
}
int query_prefix(char *w,int i,trie* it,int total)
{
    int poz = convert_char_to_int(w[i]);
    if(it->t[poz] != NULL)
    {
        //cout<<it->t[poz]<<" "<<poz<<"\n";
        total++;
        if(i+1 < strlen(w)) query_prefix(w,i+1,it->t[poz],total);
        else return total;
    }
    else return total;
}
int main()
{
    t_node = new trie;
    int k1;
    char cuv[21];
    while(fin>>k1)
    {
        fin>>cuv;
        if(k1 == 0)
        {
            add_w(cuv);
        }
        else if(k1 == 1)
        {
            delete_w(cuv,0,t_node);
        }
        else if(k1 == 2)
        {
            fout<<query_word(cuv,0,t_node)<<"\n";
        }
        else
        {
            fout<<query_prefix(cuv,0,t_node,0)<<"\n";
        }
    }
}