#include "bits/stdc++.h"
using namespace std;
 
#define ll long long
 
#define       forn(i,n)              for(int i=0;i<n;i++)
#define          all(v)              v.begin(), v.end()
#define         rall(v)              v.rbegin(),v.rend()
 
#define            pb                push_back
#define          sz(a)               (int)a.size()

const int N = 1e6 + 20;
int t[N][26], cnt[N], cnt_word[N], idx = 2;
void insert(string& s) {
    int u = 1;
    for(int i = 0; i < sz(s); ++i) {
        if(t[u][s[i] - 'a'] == 0) {
            t[u][s[i] - 'a'] = idx++;
        }
        u = t[u][s[i] - 'a'];
        ++cnt[u];
    }
    ++cnt_word[u];
}

int count(string& s) {
    int u = 1;
    for(int i = 0; i < sz(s); ++i) {
        if(!cnt[t[u][s[i] - 'a']]) return 0;
        u = t[u][s[i] - 'a'];       
    }
    return cnt_word[u];
}
int longest_prefix(string& s) {
    int u = 1, ans = 0;
    for(int i = 0; i < sz(s); ++i) {
        if(!cnt[t[u][s[i] - 'a']]) return ans;
        ++ans;
        u = t[u][s[i] - 'a'];
    }
    return ans;
}
void delete_string(string& s) {
    int u = 1;
    for(int i = 0; i < sz(s); ++i) {
        u = t[u][s[i] - 'a'];
        cnt[t[u][s[i] - 'a']]--;
    }
    --cnt_word[u];
}

void solve() {
    freopen("trie.in", "r", stdin);
    freopen("trie.out", "w", stdout);
    int a; string b;
    while(cin >> a) {
        cin >> b;
        if(a == 0) {
            insert(b);
        } else if(a == 1) {
            delete_string(b);
        } else if(a == 2) {
            cout << count(b) << "\n";
        } else {
            cout << longest_prefix(b) << "\n";
        }
    }
}   
 
int32_t main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int t = 1;
    //cin >> t;
    while(t--) {
        solve();
    }
}