#include <fstream>
using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");

struct Trie
{
  int Nr,NrSons;
  Trie * Son[26];
  Trie()
  {
    Nr = NrSons = 0;
    for(int i = 0; i < 26; ++i)
      Son[i] = NULL;
  }
};

Trie * T = new Trie;

void Insert(Trie * p, char Word[])
{
  if(Word[0] == 0)
  {
    p->Nr++;
    return;
  }
  if(p->Son[Word[0]-'a'] == 0)
  {
    p->Son[Word[0]-'a'] = new Trie;
    p->NrSons++;
  }
  Insert(p->Son[Word[0]-'a'], Word + 1);
}

int Find(Trie * p, char Word[])
{
  if(Word[0] == 0)
    return p->Nr;

  if(p->Son[Word[0]-'a'] != 0)
    return Find(p->Son[Word[0]-'a'], Word + 1);

  return 0;
}

int Prefix(Trie * p, char Word[], int k)
{
  if(Word[0] == 0)
    return k;

  if(p->Son[Word[0]-'a'] == 0)
    return k;

  return Prefix(p->Son[Word[0]-'a'], Word + 1,k + 1);
}

int Delete(Trie * p, char Word[])
{
  if(Word[0] == 0)
     p->Nr--;
  else
  if( Delete(p->Son[Word[0]-'a'], Word + 1) == 1)
  {
    p->Son[Word[0]-'a'] = 0;
    p->NrSons--;
  }

  if(p -> Nr == 0 && p -> NrSons == 0 && p != T)
  {
    delete p;
    return 1;
  }

  return 0;
}

int main()
{
  char Line[30];
  while(fin.getline(Line,30))
  {
    switch (Line[0])
    {
      case '0':
      {
        Insert(T,Line + 2);
        break;
      }
      case '1':
      {
        Delete(T,Line + 2);
        break;
      }
      case '2':
      {
        fout << Find(T,Line + 2)<< "\n";
        break;
      }
      case '3':
      {
        fout << Prefix(T,Line + 2, 0) << "\n";
        break;
      }
    }
  }
    return 0;
}