#include <fstream>
#include <cstring>
#define maxWordLength 20

struct node
{
    int occurences;

    struct node *edge[26];

    node()
    {
        occurences = 0;

        for(int i = 0; i < 26; i++)
        {
            edge[i] = NULL;
        }
    }
};

node *root = new node;

void Insert(char word[])
{
    node *current = root;

    int len = strlen(word), index;

    for(int i = 0; i < len; ++i, current = current -> edge[index]){

        index = word[i] - 'a';

        if(current -> edge[index] == NULL)
        {
            current -> edge[index] = new node;
        }
    }

    ++(current -> occurences);
}

void Delete(char word[])
{
    int len = strlen(word), index, it = -1, sons;

    node *pathStack[maxWordLength + 1], *current = root;

    pathStack[++it] = current;

    for(int i = 0; i < len; ++i, current = current -> edge[index])
    {
        index = word[i] - 'a';

        if(current -> edge[index] == NULL) return;

        pathStack[++it] = current -> edge[index];
    }

    if(current -> occurences > 1)
    {
        --(current -> occurences);

        return;
    }

    --(current -> occurences);

    for(int i = it; i; --i)
    {
        sons = 0;

        for(int j = 0; j < 26; ++j)
        {
            sons += !!(pathStack[i] -> edge[j]);
        }

        if(sons || pathStack[i] -> occurences) return;

        else
        {
            delete pathStack[i];

            pathStack[i - 1] -> edge[word[i - 1] - 'a'] = NULL;
        }
    }
}

int Search(char word[])
{
    node *current = root;

    int len = strlen(word), index;

    for(int i = 0; i < len; ++i, current = current -> edge[index])
    {
        index = tolower(word[i]) - 'a';

        if(current -> edge[index] == NULL) return 0;
    }

    return current -> occurences;
}

int LongestPrefix(char word[])
{
    node *current = root;

    int len = strlen(word), index, prefix = 0;

    for(int i = 0; i < len; ++i, current = current -> edge[index])
    {
        index = word[i] - 'a';

        if(current -> edge[index] == NULL) break;

        ++prefix;
    }

    return prefix;
}

int main()
{
    freopen("trie.in", "r", stdin);
    freopen("trie.out", "w", stdout);

    int task; char word[21];

    while(scanf("%d %s", &task, word) == 2)
    {
        switch(task)
        {
            case 0: Insert(word);
                    break;

            case 1: Delete(word);
                    break;

            case 2: printf("%d\n", Search(word));
                    break;

            case 3: printf("%d\n", LongestPrefix(word));
                    break;
        }
    }

    return 0;
}