#include<cstdio>
using namespace std;

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

const int SIGMA = 26;
int N, prefix;
char S[22];

struct Node
{
    Node* son[SIGMA];
    int nrAppear;
    int nrPrefix;
};

Node* newEmptyNode()
{
    Node* node = new Node;
    for (int i = 0; i < SIGMA; i++)
        node -> son[i] = NULL;
    node -> nrAppear = 0;
    node -> nrPrefix = 0;
    return node;
}

void Insert(Node* node, char* word)
{
    if (word[0] == 0)
        node -> nrAppear ++;
    else
    {
        if (node -> son[word[0] - 'a'] == NULL)
            node -> son[word[0] - 'a'] = newEmptyNode();

        node = node -> son[word[0] - 'a'];
        node -> nrPrefix ++;
        Insert(node, word + 1);
    }
}

void Delete(Node* node, char* word)
{
    if (word[0] == 0)
        node -> nrAppear --;
    else
    {
        if (node -> son[*word - 'a'] != NULL)
            node = node -> son[*word - 'a'];

        node -> nrPrefix --;
        Delete(node, word + 1);
    }
}

int NrAppear(Node* node, char* word)
{
    if (*word == 0)
        return node -> nrAppear;
    if (node -> son[*word - 'a'] != NULL)
        {
            node = node -> son[*word - 'a'];
            return NrAppear(node, word + 1);
        }
    return 0;
}

int Prefix(Node* node, char* word)
{
    if (*word == 0)
        return prefix;
    if (node -> son[*word - 'a'] != NULL)
    {
        node = node -> son[*word - 'a'];
        if (node -> nrPrefix != 0)
        {
            prefix ++;
            return Prefix(node, word + 1);
        }
    }
    return prefix;
}
int main()
    {
        Node *dictionary = newEmptyNode();
        while (scanf("%d ", &N) && gets(S))
        {
            if (N == 0)     Insert(dictionary, S);
            else
                if (N == 1) Delete(dictionary, S);
            else
                if (N == 2) printf("%d\n", NrAppear(dictionary, S));
            else
            {
                prefix = 0;
                printf("%d\n", Prefix(dictionary, S));
            }
        }
    }