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

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

struct trieNode* root;

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

void InsertWord(struct trieNode* root, char* key)
{
    struct trieNode* 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 DeleteWord(struct trieNode* root, char* key)
{
    struct trieNode* node = root;
    struct trieNode* node2 = root;
    int length = strlen(key);
    for(int i=0; i<length; i++)
    {
        node2 = node->child[key[i]-'a'];
        --node2->cnt;
        if(node2->cnt == 0) node->child[key[i]-'a'] = NULL;
        if(node->cnt == 0) free(node);
        node = node2;
    }
    --node2->fin;
}

int SearchWord(struct trieNode* root, char* key)
{
    struct trieNode* node = root;
    int length = strlen(key);
    int i = 0;
    while(i < length && node->child[key[i]-'a'] != NULL)
    {
        node = node->child[key[i]-'a'];
        i++;
    }
    return(i == length? node->fin : 0);
}

int prefixSearch(struct trieNode* root, char* key)
{
    struct trieNode* node = root;
    int length = strlen(key);
    int i, nr;
    i = nr = 0;
    while(i < length && node->child[key[i]-'a'] != NULL)
    {
        node = node->child[key[i]-'a'];
        i++;
        nr++;
    }
    return nr;
}

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