#include <iostream>
#include <iomanip>
#include <fstream>
#include <sstream>
#include <cstring>
#include <cstdlib>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <list>
#include <set>
#include <map>
using namespace std;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define pb push_back
#define sz size()
#define SORT(x) sort(x.begin(), x.end())
#define REVERSE(x) reverse(x.begin(), x.end())
#define REP(x, hi) for (int x=0; x<(hi); x++)
#define FOR(x, lo, hi) for (int x=(lo); x<(hi); x++)
#define FORALL(it,x) for (typeof(x.begin()) it=x.begin(); it!=x.end(); it++)
#define INFILE "trie.in" 
#define OUTFILE "trie.out"
ifstream fin (INFILE);
ofstream fout (OUTFILE);
#define CHARNR 26

struct nod{
  int val, prefs;
  nod* next[CHARNR];
  nod() : val(0), prefs(0)
  {
    memset( next, NULL, sizeof(next));
  }
};

int getval(char c)
{
  return int(c)-int('a');
}

void add(nod* t[], char w[])
{
  int pos = getval(w[0]);
  if( t[pos]==NULL )
  {
    t[pos] = new nod();
  }
  if( strlen(w)==1 )
    t[pos]->val++;
  else
  {
    t[pos]->prefs++;
    add( t[pos]->next, w+1);
  }
}

void remove(nod* t[], char w[])
{
  int pos = getval(w[0]);
  if( strlen(w)==1 )
  {
    t[pos]->val--;
    if( t[pos]->prefs==0 && t[pos]->val==0 )
    {
      delete t[pos];
      t[pos] = NULL;
    }
  }
  else
  {
    t[pos]->prefs--;
    remove(t[pos]->next, w+1);
    if( t[pos]->prefs==0 && t[pos]->val==0 )
    {
      delete t[pos];
      t[pos] = NULL;
    }
  }
}

int wordcount(nod *t[], char w[])
{
  int pos = getval(w[0]);
  if( t[pos]==NULL )
    return 0;
  if( strlen(w)==1 )
    return t[pos]->val;
  else
    return wordcount(t[pos]->next, w+1);
}

int getprefix(nod* t[], char w[])
{
  int pos = getval(w[0]);
  if( strlen(w)==0 || t[pos]==NULL || (t[pos]->prefs==0 && t[pos]->val==0) )
    return 0;
  return 1 + getprefix(t[pos]->next, w+1);
}

int main()
{
  char c, word[32];
  nod* trie[CHARNR] = {NULL};

  while( fin >> c >> word)
  {
    switch(c) {
      case '0': 
        add(trie, word);
        break;
      case '1': 
        remove(trie, word);
        break;
      case '2': 
        fout << wordcount(trie, word) << endl;
        break;
      case '3': 
        fout << getprefix(trie, word) << endl;
        break;
      default: 
        break;
    }
  }
	
	return 0;
}