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

struct Trie {
    int final = 0, n = 0;
    Trie* v[26] {};
} *root = new Trie;

void add(char* s) {
    Trie* current = root;
    int l = strlen(s);
    for(int i = 0; i < l; ++i) {
        if(current -> v[s[i] - 'a'] == NULL) {
            current -> v[s[i] - 'a'] = new Trie;
            ++current -> n;
        }
        current = current -> v[s[i] - 'a'];
    }
    ++current -> final;
}

bool remove(char* s, Trie* current) {
    if(s[0] == '\0')
        --current -> final;
    else if(remove(s+1, current -> v[s[0] - 'a'])) {
        --current -> n;
        current -> v[s[0] - 'a'] = NULL;
    }
    if(current -> final == 0 && current -> n == 0 && current != root) {
        delete current;
        return 1;
    }
    return 0;
}

int count(char* s) {
    Trie* current = root;
    int l = strlen(s);
    for(int i = 0; i < l; ++i)
        if(current -> v[s[i] - 'a'])
            current = current -> v[s[i] - 'a'];
        else
            return 0;
    return current -> final;
}

int prefix(char* s) {
    Trie* current = root;
    int i = 0, l = strlen(s);
    while(current -> v[s[i] - 'a'] && i < l) {
        current = current -> v[s[i] - 'a'];
        ++i;
    }
    return i;
}

int main() {
    ifstream fin("trie.in");
    ofstream fout("trie.out");
    int op;
    char s[21];
    while(fin >> op >> s)
        if(op == 0)
            add(s);
        else if(op == 1)
            remove(s, root);
        else if(op == 2)
            fout << count(s) << '\n';
        else
            fout << prefix(s) << '\n';
}