#include<bits/stdc++.h>
using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
struct Trie {
    int cnt, ap;
    Trie *child[26];
    Trie() {
        cnt = ap = 0;
        memset(child, 0, sizeof(child));
    }
};
int type;
string c;
Trie *T;
void ins(string s)
{
    Trie *x = T;
    for (int i=0;i<s.size();i++){
        int newn = s[i] - 'a';
        if (!x->child[newn])
            x->child[newn] = new Trie;
        x = x->child[newn];
        x->ap ++;
    }
    x->cnt ++;
}
void del(string s)
{
    Trie *x = T;
    for (int i=0;i<s.size();i++){
        int newn = s[i] - 'a';
        x = x->child[newn];
        x->ap --;
    }
    x->cnt --;
}
int appear(string s)
{
    Trie *x = T;
    for (int i=0;i<s.size();i++){
        int newn = s[i] - 'a';
        if (x->child[newn] && x->child[newn]->ap)
            x = x->child[newn];
        else
            return 0;
    }
    return x->cnt;
}
int pref(string s)
{
    Trie *x = T;
    int lg = 0;
    for (int i=0;i<s.size();i++){
        int newn = s[i] - 'a';
        if (x->child[newn] && x->child[newn]->ap)
            x = x->child[newn];
        else
            return lg;
        lg ++;
    }
    return lg;
}
int main()
{
    T = new Trie;
    while(fin >> type >> c) {
        if (type == 0) {
            ins(c);
        }else if (type == 1){
            del(c);
        }else if (type == 2){
            fout << appear(c) << '\n';
        }else{
            fout << pref(c) << '\n';
        }
    }
    return 0;
}