#include <bits/stdc++.h>

using namespace std;

const int SIGMA = 26;
const int NMAX = 1e5;
const int ROOT = 0;

struct trie {
    trie* link[SIGMA] = {};
    int aparitii;
    int prefix;
};

trie* root = new trie;

void add( trie* root, char* s ) {
    if ( *s == NULL ) {
        root->aparitii ++;
    } else {
        if ( root->link[*s - 'a'] == NULL )
            root->link[*s - 'a'] = new trie;
        root->link[*s - 'a']->prefix ++;
        add( root->link[*s - 'a'], s + 1 );
    }
}
void del( trie* root, char* s ) {
    if ( *s == NULL ) {
        root->aparitii --;
    } else {
        root->link[*s - 'a']->prefix --;
        del( root->link[*s - 'a'], s + 1 );
    }
}
int cnt( trie* root, char* s ) {
    if ( *s == NULL ) return root->aparitii;
    if ( root->link[*s - 'a'] == NULL ) return 0;
    return cnt( root->link[*s - 'a'], s + 1 );
}
int lcp( trie* root, char* s, int len ) {
    if ( *s == NULL ) return len;
    if ( root->link[*s - 'a'] == NULL || root->link[*s - 'a']->prefix == 0 ) return len;
    return lcp( root->link[*s - 'a'], s + 1, len + 1 );
}
int main() {
    ifstream fin( "trie.in" );
    ofstream fout( "trie.out" );
    int cer;
    char s[30];

    while ( fin >> cer >> s ) {
        switch ( cer ) {
        case 0:
            add( root, s );
            break;
        case 1:
            del( root, s );
            break;
        case 2:
            fout << cnt( root, s ) << '\n';
            break;
        case 3:
            fout << lcp( root, s, 0 ) << '\n';
            break;
        }
    }
    return 0;
}