#include <fstream>
#include <string>
#include <cstring>
#include <iterator>
using namespace std;

ifstream fi("trie.in");
ofstream fo("trie.out");
string w;

struct trie { int apar, cuv; trie* r['z'-'a'+1]; } *root;

inline trie *attempt(trie* &where) {
    if (where == NULL) {
        where = new trie;
        memset(where, 0, sizeof(trie));
    }
    return where;
}

bool rem(trie *p, int poz) {
    p->cuv --;
    if (poz == w.size()) {
        p->apar --;
    } else if (rem(p->r[w[poz]-'a'], poz+1) == 1)
        p->r[w[poz]-'a'] = NULL;
    if (! p->cuv && p != root) {
        delete(p);
        return 1;
    }
    return 0;
}

int main()
{
    int op, i;
    attempt(root);

    while (fi >> op >> w) {
        trie *p = root;
        if (op == 0) {
            p->cuv ++;
            for (i = 0; i < w.size(); ++i)
                (p = attempt(p->r[w[i]-'a'])) -> cuv ++;
            p->apar ++;
        } else if (op == 1) {
            rem(p, 0);
            // (eventual p->howmanywords) - nu neaparat
            // sterg recursiv ce ramane pe dinafara
        } else if (op == 2) {
            for (i = 0; i < w.size(); ++i)
                p = attempt(p->r[w[i]-'a']);
            fo << p->apar << "\n";
        } else if (op == 3) {
             for (i = 0; i < w.size(); ++i)
                 if ((p = p->r[w[i]-'a']) == NULL) {
                     fo << i << "\n";
                     break;
                 }
        }
    }
    return 0;
}