#include <bits/stdc++.h>
#define DIM 1000001

using namespace std;

ifstream fin("trie.in");

ofstream fout("trie.out");

vector < pair <int, char> > G[DIM];

int dp[DIM];

int task, i, nodes = 1, answer, lg;

string s;

void add(int node){


    int next_node = -1;

    dp[node] += 1;

    if(i == s.size())

        return ;

    for(auto k : G[node])

        if(k.second == s[i]){

            next_node = k.first;

            break;

        }

    if(next_node < 0){

        ++nodes;

        G[node].push_back(make_pair(nodes, s[i]));

        next_node = nodes;

    }

    ++i;

    add(next_node);

}

void del(int node){

    dp[node] -= 1;

    if(i == s.size())

        return ;

    int next_node = -1;

    for(auto k : G[node])

        if(k.second == s[i]){

            next_node = k.first;

            break;

        }

    ++i;

    del(next_node);

}

void frequency(int node){

    if(node == -1){

        answer = 0;

        return ;

    }

    answer = min(answer, dp[node]);

    if(i == s.size()){

        for(auto k : G[node])

            answer -= dp[k.first];

        return ;

    }

    int next_node = -1;

    for(auto k : G[node])

        if(k.second == s[i]){

            next_node = k.first;

            break;

        }

    ++i;

    frequency(next_node);

}

void get_prefix(int node){

    if(node == -1)

        return ;

    answer = min(answer, dp[node]);

    if(i == s.size())

        return ;

    if(answer <= 1)

        return ;

    int next_node = -1;

    if(node != 1)

        ++lg;

    for(auto k : G[node])

        if(k.second == s[i]){

            next_node = k.first;

            break;

        }

    ++i;

    get_prefix(next_node);

}

int main(){

    while(fin >> task){

        fin >> s;

        i = 0;

        if(task == 0)

            add(1);

        if(task == 1)

            del(1);

        if(task == 2){

            answer = 1e9;

            frequency(1);

            fout << answer << "\n";

        }

        if(task == 3){

            answer = 1e9;

            lg = 0;

            get_prefix(1);

            fout << lg << "\n";

        }

    }

}