#include<fstream>
#include<string.h>
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");
int x;
char cuv[20];
class nod
{   public:
	int nr_cuvinte,pref_cuv;
	nod *fii[26];
}*rad=new nod;
void ad_cuv(char *w)
{   
	nod *aux=rad;
	for(int i=0;i<strlen(w);i++)
	{
		if(aux->fii[w[i]-'a']==NULL)
		{   nod *q=new nod;
			aux->fii[w[i]-'a']=q;
			++aux->pref_cuv;
			aux=aux->fii[w[i]-'a'];
			continue;
		}
		++aux->pref_cuv;
		aux=aux->fii[w[i]-'a'];
	}
	++aux->nr_cuvinte;
	++aux->pref_cuv;
}
void delete_cuv(char *w)
{
	nod *aux=rad;
	for(int i=0;i<strlen(w);i++)
	{
		aux=aux->fii[w[i]-'a'];
		--aux->pref_cuv;
	}
	--aux->nr_cuvinte;
}
void print_nrcuv(char *w)
{
	nod *aux=rad; int i;
	for(i=0;i<strlen(w)&&aux->fii[w[i]-'a']!=NULL;i++)
	{
		aux=aux->fii[w[i]-'a'];
	}
	g<<aux->nr_cuvinte*(i==strlen(w))<<'\n';
}
void prefix_maxim(char *w)
{
	int nr=0;
	nod *aux=rad;
	for(int i=0;i<strlen(w)&&aux->fii[w[i]-'a']!=NULL;i++)
	{
		aux=aux->fii[w[i]-'a'];
		if(aux->pref_cuv<=0) break;
		++nr;
    }
    g<<nr<<'\n';
  
}
int main()
{
	while(f>>x>>cuv)
	{   
		switch(x)
		{
			case 0:
			ad_cuv(cuv);
			break;
			case 1:
			delete_cuv(cuv);
			break;
			case 2:
			print_nrcuv(cuv);
			break;
			case 3:
			prefix_maxim(cuv);
			break;
		}
	}
  return 0;
}