#include <iostream>
#include <stdio.h>

using namespace std;


class Trie
{
private:
  Trie *Edge[27];
  int words;
  int cEdge;

public:
  Trie()
  {
    for (size_t i = 0; i < 27; i++)
      this->Edge[ i ] = 0;
    this->words = 0;
    this->cEdge   = 0;
  }

  ~Trie()
  {

  }

public:
  inline int AlphaToInt(char chr)
  {
    return chr - 'a';
  }

  inline void Push(char *str)
  {
    //printf("[%s]->[%c]->[%d]\n", str, *str, AlphaToInt(*str));
    if (*str == 0)
    {
      this->words++;
      return;
    }

    if (this->Edge[ AlphaToInt(*str) ] == 0)
    {
      this->Edge[ AlphaToInt(*str) ] = new Trie();
      this->cEdge++;
    }

    this->Edge[ AlphaToInt(*str) ]->Push( str + 1 );
  }

  inline void Erase(char *str)
  {
    if (*str == 0)
      this->words--;
    else if (this->Edge[ AlphaToInt(*str) ])
    {
      this->Edge[ AlphaToInt(*str) ]->Erase( str + 1);

      //Sterg muchia doar daca ea nu mai leaga o alta muchie.
      if (this->Edge[ AlphaToInt(*str) ]->cEdge == 0 && this->Edge[ AlphaToInt(*str) ]->words == 0)
      {
        delete this->Edge[ AlphaToInt(*str) ];
        this->Edge[ AlphaToInt(*str) ] = 0;
        this->cEdge--;
      }
    }
  }

  inline int Query(char *str)
  {
    if (*str == 0)
      return this->words;

    if (this->Edge[ AlphaToInt(*str) ])
      return this->Edge[ AlphaToInt(*str) ]->Query( str + 1 );

    return 0;
  }

  inline int PrefixLength(char *str)
  {
    if (*str == 0)
      return 0;

    if (this->Edge[ AlphaToInt(*str) ])
      return 1 + this->Edge[ AlphaToInt(*str) ]->PrefixLength( str + 1 );

    return 0;
  }

};

int main()
{
  FILE * f = fopen("trie.in", "r");
  FILE * g = fopen("trie.out", "w");

  if (f && g)
  {
    Trie *T = new Trie();

    int p;
    char w[30];

    fscanf(f, "%d %s", &p, &w);
    while (!feof(f))
    {
      if (p == 0) T->Push(w);
      else if (p == 1) T->Erase(w);
      else if (p == 2) fprintf(g, "%d\n", T->Query(w));
      else if (p == 3) fprintf(g, "%d\n", T->PrefixLength(w));

      fscanf(f, "%d %s", &p, &w);
    }

    fclose(f);
    fclose(g);
  }

  return 0;
}