#include <bits/stdc++.h>
#define int long long
#define ll pair<long long, long long>
using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");

struct trie {
    int cnt, nr_sons;
    trie *sons[26];
    trie() {
        for (int i = 0; i < 26; ++i) {
            sons[i] = NULL;
        }
        cnt = nr_sons = 0;
    }
};
trie *root = new trie;

void add_word(char *word) {
    int len = strlen(word);
    trie *cur_node = root;
    for (int i = 0; i < len; ++i) {
        if (cur_node->sons[word[i] - 'a'] == NULL) {
            cur_node->sons[word[i] - 'a'] = new trie;
            cur_node->nr_sons++;
        }
        cur_node = cur_node->sons[word[i] - 'a'];
        if (i == len - 1) {
            cur_node->cnt++;
        }
    }

}

bool delete_word(trie *node, char *word) {
    if (*word == '\0') {
        node->cnt--;
    } else if (delete_word(node->sons[*word - 'a'], word + 1)) {
        node->sons[*word - 'a'] = NULL;
        node->nr_sons--;
    }
    if (node->nr_sons == 0 and node->cnt == 0 and node != root) {
        delete node;
        return true;
    }
    return false;
}

int find_occurences(char *word) {
    int len = strlen(word);
    trie *cur_node = root;
    for (int i = 0; i < len; ++i) {
        if (!cur_node->sons[word[i] - 'a']) {
            return 0;
        }
        cur_node = cur_node->sons[word[i] - 'a'];
    }
    return cur_node->cnt;
}

int find_prefix(char *word) {
    int len = strlen(word);
    trie *cur_node = root;
    for (int i = 0; i < len; ++i) {
        if (!cur_node->sons[word[i] - 'a']) {
            return i;
        }
        cur_node = cur_node->sons[word[i] - 'a'];
    }
    return len;
}

int32_t main() {
    //ios_base::sync_with_stdio(false), cin.tie(NULL);
    int tests = 1;
    //cin >> tests;
    while (tests--) {
        char query[30];
        while (fin >> query) {
            char word[30];
            fin >> word;
            if (query[0] == '0') {
                add_word(word);
            } else if (query[0] == '1') {
                delete_word(root, word);
            } else if (query[0] == '2') {
                fout << find_occurences(word) << '\n';
            } else {
                fout << find_prefix(word) << '\n';
            }
        }
    }
    return 0;
}