#include<cstdio>
#include<fstream>
using namespace std;
int key;
char word[25],*p;
struct trie
{
	int ok, nr;
	trie *next[26];
	trie()
	{
		for(int i=0;i<26;i++)
			next[i]=0;
		ok=0;
		nr=0;
	}
}*first, *aux;
int main()
{
	int lit,NR;
	freopen("trie.in","r",stdin);
	freopen("trie.out","w",stdout);
	first=new trie;
	for(;scanf("%d%s", &key, word)+1;)
	{
		if(key==0)
		{
			for(aux=first,p=word;*p;p++)
			{
				lit=*p-'a';
				if(!aux->next[lit])
					aux->next[lit]=new trie;
				aux=aux->next[lit];
				aux->nr++;
			}
			aux->ok++;
			continue;
		}
		if(key==1)
		{
			for(aux=first,p=word;*p;p++)
			{
				lit=*p-'a';
				aux=aux->next[lit];
				aux->nr--;
			}
			aux->ok--;
			continue;
		}
		if(key==2)
		{
			for(aux=first, p=word;*p;p++)
			{
				lit=*p-'a';
				aux=aux->next[lit];
				if(!aux)
					break;
			}
			if(aux!=0)
				printf("%d\n", aux->ok);
			else
				printf("0\n");
			continue;
		}
		if(key==3)
		{
			NR=0;
			for(aux=first,p=word;*p;p++)
			{
				lit=*p-'a';
				aux=aux->next[lit];
				if(!aux||!aux->nr)
					break;
				NR++;
			}
			printf("%d\n",NR);
		}
	}
	return 0;
}