#include <bits/stdc++.h>

struct Trie {
        Trie *ch[28] ;
        int nrcuv, nrpref ;
        Trie() {
                for (int i = 0 ; i <= 27 ; ++ i) { this -> ch[i] = NULL ; }
                this -> nrcuv = this -> nrpref = 0 ;
        }
};

Trie *root = new Trie ;

void add_in_trie(std::string nw, Trie *node) {
        for (auto it : nw) {
                if (node -> ch[it - 'a'] == NULL) { node -> ch[it - 'a'] = new Trie ; }
                node = node -> ch[it - 'a'] ; node -> nrpref ++ ;
        }
        node -> nrcuv ++ ;
}

bool erase_from_trie(Trie *&node, std::string nw, int index) {
        node -> nrpref -- ;
        if (index == nw.size()) { node -> nrcuv -- ;
        } else { erase_from_trie(node -> ch[nw[index] - 'a'], nw, index + 1) ; }
        if (node != root && node -> nrpref == 0) {
                delete node ,node = NULL ;
        }
}

int aparitii(std::string nw, Trie *node) {
        for (auto it : nw) {
                node = node -> ch[it - 'a'] ;
        }
        return node -> nrcuv ;
}

int prefix(std::string nw, Trie *node) {
        int i ;
        for (i = (0) ; i < nw.size() ; ++ i) {
                if (node -> ch[nw[i] - 'a'] == NULL) { break ; }
                node = node -> ch[nw[i] - 'a'] ;
        }
        return i ;
}

int main() {
        freopen("trie.in", "r", stdin) ;
        freopen("trie.out", "w", stdout) ;
        int type, ans ;
        std::string ss ;
        while (std::cin >> type >> ss) {
                if (type == 0) {
                        add_in_trie(ss, root) ;
                } else if (type == 1) {
                        erase_from_trie(root, ss, 0) ;
                } else if (type == 2) {
                        ans = aparitii(ss, root) ;
                        std::cout << ans << '\n' ;
                } else {
                        ans = prefix(ss, root) ;
                        std::cout << ans << '\n' ;
                }
        }
}