#include<stdio.h>
#include <cstring>

using namespace std;

#define MAXL 20
#define ALFSIZE 26

typedef struct nod{
	int freq, nbfii;
	nod* fii[ALFSIZE];
	nod() {
		freq = nbfii = 0;
		memset( fii, NULL, sizeof( fii ) );
	}
}nod;

nod* root;

#define index (sir[0]-'a')

void addcuv(char* sir){
	nod* crt=root;
	while(sir[0]){
		if(crt->fii[index]==NULL){
			crt->fii[index]=new nod;
			crt->nbfii++;
		}
		crt=crt->fii[index];
		sir++;
	}
	// ultimul caracter
	crt->freq++;
}

bool removecuv(char* sir,nod* p){
	if(sir[0]==0){
		p->freq--;
	}
	else{
		bool del=removecuv(sir+1,p->fii[index]);
		if(del){
			p->fii[index]=NULL;
			p->nbfii--;
		}
	}

	if(p->freq==0 && p->nbfii==0 && p!=root){
		delete p;
		return true;
	}
	else
		return false;
}

int count(char* sir){
	nod* crt=root;
	while(sir[0]){
		if(crt->fii[index]==NULL){
			return 0;
		}
		else{
			crt=crt->fii[index];
		}
		sir++;
	}
	// am parcurs tot sirul
	return crt->freq;
}

int prefix(char* sir){
	nod* crt=root;
	int prefix=0;
	while(sir[0]){
		if(crt->fii[index]==NULL){
			return prefix;
		}
		else{
			crt=crt->fii[index];
			prefix++;
		}
		sir++;
	}
	return prefix;
}

int main(){
	
	freopen("trie.in","rt",stdin);
	//freopen("test20.in","rt",stdin);
	freopen("trie.out","wt",stdout);
	
	root=new nod;
	
	char tip,line[21];
	
	while( !feof( stdin ) ) {
	
		scanf("%c %s\n",&tip,&line);
		
		switch(tip){
			case '0': // adauga o aparitie
				addcuv(line);
				break;
			case '1': // sterge o aparitie
				removecuv(line,root);
				break;
			case '2': // numarul de aparitii
				printf("%d\n",count(line));
				break;
			case '3': // lungime prefix maxim
				printf("%d\n",prefix(line));
				break;
		}
	}
	
	return 0;
}