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

#define ALF 26

struct node {
    int nrChild, key;
    node* next[ALF];

    node() {
        nrChild = key = 0;
        memset(next, 0, sizeof(next));
    }
};

FILE* f = fopen("trie.in", "r");
FILE* g = fopen("trie.out", "w");

node root;
char buf[25];

void add(node* ptr, char* c)
{
    while (*c != '\n') {
        if (ptr->next[*c - 'a'] == 0) {
            ptr->next[*c - 'a'] = new node;
            ptr->nrChild++;
        }
        ptr = ptr->next[*c - 'a'];
        c++;
    }
    ptr->key++;
}

bool del(node* ptr, char* c)
{
    if (*c == '\n') {
        ptr->key--;
    } else if (del(ptr->next[*c - 'a'], c + 1) == true) {
        ptr->next[*c - 'a'] = 0;
        ptr->nrChild--;
    }

    if (ptr->key == 0 && ptr->nrChild == 0 && ptr != &root) {
        delete ptr;
        return true;
    }
    return false;
}

int numAparitions(node* ptr, char* c)
{
    while (*c != '\n') {
        if (ptr->next[*c - 'a'] == 0) {
            return 0;
        }
        ptr = ptr->next[*c - 'a'];
        c++;
    }
    return ptr->key;
}

int maxPrefix(node* ptr, char* c)
{
    int nr = 0;
    while (*c != '\n' && ptr->next[*c - 'a'] != 0) {
        ptr = ptr->next[*c - 'a'];
        nr++, c++;
    }
    return nr;
}

int main()
{
    while (fgets(buf, sizeof(buf), f)) {
        switch (buf[0]) {
            case '0': add(&root, buf + 2); break;
            case '1': del(&root, buf + 2); break;
            case '2': fprintf(g, "%d\n", numAparitions(&root, buf + 2)); break;
            case '3': fprintf(g, "%d\n", maxPrefix(&root, buf + 2));
        }
    }
}