#include <cstdio>
#include <cstring>

const int LINEMAX = 30;

char s[LINEMAX];

struct Trie {
    int cnt, noChildren;
    Trie *child[26];

    Trie () {
        cnt = noChildren = 0;
        memset (child, 0, sizeof (child));
    }
};

Trie *T = new Trie;

void insertTrie (Trie *node, char *s) {
    if (*s == NULL) {
        node-> cnt++;
        return;
    }

    if (node-> child[*s - 'a'] == 0) {
        node-> child[*s - 'a'] = new Trie;
        node-> noChildren++;
    }

    insertTrie (node-> child[*s - 'a'], s + 1);
}

int removeTrie (Trie *node, char *s) {
    if (*s == NULL) {
        node-> cnt--;

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

    if (removeTrie (node-> child[*s - 'a'], s + 1) == 1) { //if the node is deleted
        node-> noChildren--;
        node-> child[*s - 'a'] = 0;

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

    return 0;
}

int countTrie (Trie *node, char *s) {
    if (*s == NULL) {
        return node-> cnt;
    }

    if (node-> child[*s - 'a']) {
        return countTrie (node-> child[*s - 'a'], s + 1);
    }
    return 0;
}

int maxPrefixTrie (Trie *node, char *s, int ans = 0) {
    if (*s == NULL || !node-> child[*s - 'a']) {
        return ans;
    }

    return maxPrefixTrie (node-> child[*s - 'a'], s + 1, ans + 1);
}

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

    gets (s);
    while ( !feof (stdin)) {
        switch (s[0] - '0') {
            case 0: insertTrie (T, s + 2); break;
            case 1: removeTrie (T, s + 2); break;
            case 2: printf ("%d\n", countTrie (T, s + 2)); break;
            case 3: printf ("%d\n", maxPrefixTrie (T, s + 2)); break;
        }

        gets (s);
    }

    return 0;
}