#include<cstdio>
#include<cstring>
#include<cstdlib>
#define SIGMA 26
#define MAX_LEN 20
using namespace std;

struct trie
{
    int cnt, fin;
    struct trie* child[SIGMA];
};

struct trie* root;

struct trie* getNode()
{
    struct trie* node;
    node = (struct trie*)malloc(sizeof(struct trie));
    node->cnt = node->fin = 0;
    for(int i=0; i<SIGMA; i++)
        node->child[i] = NULL;
    return node;
};

void Insert(struct trie* root, char* key)
{
    struct trie* node = root;
    int length = strlen(key);
    for(int i=0; i<length; i++)
    {
        if(node->child[key[i]-'a'] == NULL)
            node->child[key[i]-'a'] = getNode();
        node = node->child[key[i]-'a'];
        ++node->cnt;
    }
    ++node->fin;
}

void Delete(struct trie* root, char* key)
{
    struct trie* node = root;
    struct trie* tmp = root;
    int length = strlen(key);
    for(int i=0; i<length; i++)
    {
        tmp = node->child[key[i]-'a'];
        --tmp->cnt;
        if(tmp->cnt == 0) node->child[key[i]-'a'] = NULL;
        if(node->cnt == 0) free(node);
        node = tmp;
    }
    --tmp->fin;
}

int Search(struct trie* root, char* key)
{
    struct trie* node = root;
    int length = strlen(key);
    bool ok = true;
    for(int i=0; i<length && ok; i++)
    {
        if(node->child[key[i]-'a'] == NULL)
            ok = false;
        node = node->child[key[i]-'a'];
    }
    if(ok) return node->fin;
    else return 0;
}

int prefixSearch(struct trie* root, char* key)
{
    struct trie* node = root;
    int length = strlen(key);
    int nr = 0;
    bool ok = true;
    for(int i=0; i<length && ok; i++)
    {
        if(node->child[key[i]-'a'] == NULL)
            ok = false;
        else ++nr;
        node = node->child[key[i]-'a'];
    }
    return nr;
}

int main()
{
    char word[MAX_LEN + 1];
    int op;
    FILE *fin, *fout;
    fin = fopen("trie.in","r");
    fout = fopen("trie.out","w");
    root = getNode();
    root->cnt = 11;
    while(!feof(fin))
    {
        fscanf(fin,"%d",&op);
        fscanf(fin,"%s\n",word);
        if(!op) Insert(root,word);
        else if(op == 1) Delete(root,word);
        else if(op == 2) fprintf(fout,"%d\n",Search(root,word));
        else fprintf(fout,"%d\n",prefixSearch(root,word));
    }
    fclose(fin);
    fclose(fout);
    return 0;
}