#include <iostream>
#include <cstdio>
#include <cstring>
#define ch (*s - 'a')

using namespace std;

struct Trie {
    int cnt, nrsons;
    Trie *son[26];

    Trie() {
        cnt = nrsons = 0;
        memset(son, 0, sizeof(son));
    }
};

Trie *T = new Trie;

void ins(Trie *node, char *s)
{
    if (*s == '\0') {
        node->cnt++;
        return;
    }

    if (node->son[ch] == 0) {
        node->son[ch] = new Trie;
        node->nrsons++;
    }

    ins(node->son[ch], s + 1);
}

int del(Trie *node, char *s)
{
    if (*s == '\0')
        node->cnt--;
    else if (del(node->son[ch], s + 1)) {
        node->son[ch] = 0;
        node->nrsons--;
    }

    if (node->cnt == 0 && node->nrsons == 0 && node != T) {
        delete node;
        return 1;
    }
    
    return 0;
}

int freq(Trie *node, char *s)
{
    if (*s == '\0')
        return node->cnt;
    if (node->son[ch])
        return freq(node->son[ch], s + 1);
    return 0;
}

int pref(Trie *node, char *s, int k)
{
    if (*s == '\0' || node->son[ch] == 0)
        return k;
    return pref(node->son[ch], s + 1, k + 1);
}

int main()
{
    char line[32];
    char word[32];
    int op;

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

    while (fgets(line, 32, stdin)) {
        sscanf(line, "%d %s", &op, word);
        switch(op) {
            case 0:
                ins(T, word);
                break;
            case 1:
                del(T, word);
                break;
            case 2:
                printf("%d\n", freq(T, word));
                break;
            case 3:
                printf("%d\n", pref(T, word, 0));
                break;
        }
    }

    return 0;
}