/**
 * Author: Andu Scheusan (not_andu)
 * Created: 16.12.2023 21:45:43
*/

#include <bits/stdc++.h>
#pragma GCC optimize("O3")

using namespace std;

#define INFILE "trie.in"
#define OUTFILE "trie.out"

typedef long long ll;

class Trie{

private:
    int cnt = 0;
    int level = 0;
    Trie *children[26] = {};

public:

    void insert(string s, int position = 0){
        ++level;
        if(s.size() == position) ++cnt;
        else{
            int to = s[position] - 'a';
            if(!children[to]) children[to] = new Trie;
            children[to] -> insert(s, position + 1);
        }
    }

    void erase(string s, int position = 0){
        --level;
        if(s.size() == position) --cnt;
        else{
            int to = s[position] - 'a';
            children[to] -> erase(s, position + 1);
            if(!children[to] -> level){
                delete children[to];
                children[to] = nullptr;
            }
        }
    }

    int count(string s, int poisition = 0){
        if(poisition == s.size()) return cnt;
        int to = s[poisition] - 'a';
        if(!children[to]) return 0;
        return children[to] -> count(s, poisition + 1);
    }

    int longestCommonPrefix(string s, int position = 0){
        if(position == s.size()) return 0;
        int to = s[position] - 'a';
        if(!children[to]) return 0;
        return 1 + children[to] -> longestCommonPrefix(s, position + 1);
    }

};

void solve(){

    Trie trie;

    int type;
    string word;

    while(cin >> type >> word){
        if(type == 0){
            trie.insert(word);
        }
        else if(type == 1){
            trie.erase(word);
        }
        else if(type == 2){
            cout << trie.count(word) << '\n';
        }
        else{
            cout << trie.longestCommonPrefix(word) << '\n';
        }
    }

}

int main(){
    
    ios_base::sync_with_stdio(false);

    freopen(INFILE, "r", stdin);
    freopen(OUTFILE, "w", stdout);

    cin.tie(nullptr);
    cout.tie(nullptr);

    solve();

    return 0;
}