#include <bits/stdc++.h>

const int SIGMA = 26;

using namespace std;

ifstream fin("trie.in");
ofstream fout("trie.out");

class Node {
public:
    int nrap, nrc;
    Node *fii[SIGMA];

    Node() {
        for(int i = 0; i < SIGMA; i++)
            fii[i] = NULL;

        nrap = nrc = 0;
    }
};

Node* insert_trie(Node* node, char *s) {
    if(node == NULL) node = new Node;

    node-> nrap++;

    if(s[0] == '\0')
        node-> nrc++;
    else  node-> fii[s[0] -'a'] = insert_trie(node-> fii[s[0] - 'a'], s + 1);

    return node;
}

Node* delete_trie(Node* node, char *s) {
    node-> nrap--;

    if(s[0] == '\0')
        node-> nrc--;
    else node-> fii[s[0] - 'a'] = delete_trie(node-> fii[s[0] - 'a'], s + 1);

    if(node-> nrap == 0) node = NULL;

    return node;
}

int nrap(Node* node, char *s) {
    if(node == NULL)
        return 0;

    if(s[0] == '\0') return node-> nrc;

    return nrap(node-> fii[s[0] - 'a'], s + 1);
}

int prefix(Node* node, char *s) {
    if(node == NULL)
        return -1;

    if(s[0] == '\0') return 0;

    return 1 + prefix(node-> fii[s[0] - 'a'], s + 1);
}

int main() {
    Node* trie = NULL;
    int op;
    char s[21];

    while(fin >> op) {
        fin >> s;
        if(op == 0) trie = insert_trie(trie, s);
        if(op == 1) trie = delete_trie(trie, s);
        if(op == 2) fout << nrap(trie, s) << '\n';
        if(op == 3) fout << prefix(trie, s) << '\n';
    }

    return 0;
}