#include <bits/stdc++.h>
using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
int c;
string s;
struct Tnode {
    int cnt, fii;
    Tnode* v[26];
    Tnode() {
        cnt=fii=0;
        for (int i=0; i<=25; i++) v[i]=NULL;
    }
};
Tnode *radacina=new Tnode;
void add(Tnode* nod, string s, int i) {
    if (i==s.size()) {
        nod->cnt++;
        return ;
    }
    if (nod->v[s[i]-'a']==NULL) {
        nod->v[s[i]-'a']=new Tnode;
        nod->fii++;
    }
    add(nod->v[s[i]-'a'], s, i+1);
}
void deletee(Tnode* nod, string s, int i) {
    if (i==s.size()) {
        nod->cnt--;
        if (nod->cnt==0 && nod->fii==0 && nod!=radacina) {
            nod=NULL;
        }
        return ;
    }
    else {
        deletee(nod->v[s[i]-'a'], s, i+1);
        if (nod->v[s[i]-'a']==NULL) nod->fii--;
        if (nod->cnt==0 && nod->fii==0 && nod!=radacina) {
            nod=NULL;
        }
    }

}
void cntt(Tnode* nod, string s, int i) {
    if (i==s.size()) {
        fout<<nod->cnt<<'\n';
        return ;
    }
    if (nod->v[s[i]-'a']==NULL || (nod->v[s[i]-'a']->cnt==0 && nod->v[s[i]-'a']->fii==0)) {
        fout<<0<<'\n';
        return ;
    }
    cntt(nod->v[s[i]-'a'], s, i+1);
}
void pref(Tnode* nod, string s, int i) {
    if (i==s.size()) {
        fout<<i<<'\n';
        return ;
    }
    if (nod->v[s[i]-'a']==NULL || (nod->v[s[i]-'a']->cnt==0 && nod->v[s[i]-'a']->fii==0)) {
        fout<<i<<'\n';
        return ;
    }
    pref(nod->v[s[i]-'a'], s, i+1);
}
int main()
{
    while (fin>>c>>s) {
        if (c==0) add(radacina, s, 0);
        if (c==1) deletee(radacina, s, 0);
        if (c==2) cntt(radacina, s, 0);
        if (c==3) pref(radacina, s, 0);
    }
    return 0;
}