#include <fstream>
#include <cstring>
const int NMAX=25;

using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");

struct Nod
{
  int nrc, ncopii;
  Nod* l[26];

  Nod()
  {
    ncopii=0;
    nrc=0;
    for(int i=0; i<26; i++) l[i]=NULL;
  }
};

void ins(Nod*, char*, int);
bool rem(Nod*, char*, int);
int cnt(Nod*, char*, int);
int pref_com_max(Nod*, char*, int, int);
bool elim(Nod*);

char s[NMAX];

int main()
{
  int tip;
  Nod* root=new Nod;
  while(fin>>tip>>s)
  {
    if(tip==0) ins(root, s, strlen(s));
    else if(tip==1) rem(root, s, strlen(s));
    else if(tip==2) fout<<cnt(root, s, strlen(s))<<'\n';
    else fout<<pref_com_max(root, s, strlen(s), 0)<<'\n';
  }
  return 0;
}

void ins(Nod* n, char* cuv, int lg)
{
  if(lg==0)
  {
    n->nrc++;
    return;
  }
  if(n->l[cuv[0]-'a']==NULL)
  {
    n->ncopii++;
    n->l[cuv[0]-'a']= new Nod;
  }
  ins(n->l[cuv[0]-'a'], (cuv+1), lg-1);
}

bool should_rem(Nod* n)
{
  return (n->nrc==0 && n->ncopii==0);
}

bool rem(Nod* n, char* cuv, int lg)
{
  if(lg==0)
  {
    n->nrc--;
    return should_rem(n);
  }
  else if(rem(n->l[cuv[0]-'a'], (cuv+1), lg-1))
  {
    n->l[cuv[0]-'a']=NULL;
    n->ncopii--;
    return should_rem(n);
  }
  return false;
}

int cnt(Nod* n, char* cuv, int lg)
{
  if(lg==0) return(n->nrc);
  if(n->l[cuv[0]-'a']!=NULL) return cnt(n->l[cuv[0]-'a'], cuv+1, lg-1);
  return 0;
}

int pref_com_max(Nod* n, char* cuv, int lg, int lvl)
{
  if(lg==0) return 0;
  if(n->l[cuv[0]-'a']!=NULL)
  {
    int comp=pref_com_max(n->l[cuv[0]-'a'], cuv+1, lg-1, lvl+1);
    if(n->ncopii>=1) return max(lvl+1, comp);
    return comp;
  }
  return 0;
}