#include <fstream>
#include <string>
using namespace std;
const int NrCar='z'-'a'+1,NMAX=20;
class trie{
  public:
   int nr_words,nr_sons;
   trie *leg[NrCar];
   trie(){
     nr_words=nr_sons=0;
     memset(leg,0,sizeof(leg));
     }
   ~trie(){
     delete [] leg;
     }
   void add(string word);
   int search(string word);
   void erase(string word);
   int prefix(string word);
   };
void trie::add(string word){
     int i;
     trie *r=this;
     for (i=0;i<word.length();++i){
         if (!r->leg[word[i]-'a'])
          r->leg[word[i]-'a']=new trie(),++r->nr_sons;
         r=r->leg[word[i]-'a'];}
     r->nr_words++;
     }
int trie::search(string word){
    int i;
    trie *r=this;
    for (i=0;i<word.length();++i){
        if (!r->leg[word[i]-'a']) return 0;
        r=r->leg[word[i]-'a'];}
    return r->nr_words;
    }
int trie::prefix(string word){
    int i;
    trie *r=this;
    for (i=0;i<word.length();++i){
        if (!r->leg[word[i]-'a']) return i;
        r=r->leg[word[i]-'a'];}
    return i;
    }
void trie::erase(string word){
     int i;
     trie *r=this,*p[NMAX];
     for (i=0;i<word.length();++i){
        r=r->leg[word[i]-'a'];
        p[i]=r;}
     r->nr_words--;
     for (i--;i>0;i--)
      if (p[i]->nr_sons > 0 || p[i]->nr_words>0) return;
        else {delete p[i];p[i-1]->nr_sons--;p[i-1]->leg[word[i]-'a']=0;}
     }

ifstream f("trie.in");
ofstream g("trie.out");
string s,word;
trie t,*r=new trie();
int main(){
    t=*r;
    while (!f.eof()){
      getline(f,s);
      if (s.length()<3) continue;
      word=s.substr(2,NMAX);
      switch (s[0]){
        case '0': t.add(word);break;
        case '1': t.erase(word);break;
        case '2': g<<t.search(word)<<'\n';break;
        case '3': g<<t.prefix(word)<<'\n';break;
        };
      }
    return 0;
}