#include <cstdio>

const int SIZE('z' - 'a' + 1);

struct trie
{
	int prefix;
	int words;
	struct trie *node [SIZE];
};

inline void initialize (struct trie *&vertex)
{
	vertex = new struct trie( );
}

inline void insert (struct trie *&vertex, const char *word)
{
	if (!vertex)
		initialize(vertex);
	struct trie *iterator(vertex);
	while (*word)
	{
		++iterator->prefix;
		if (!iterator->node[*word - 'a'])
			initialize(iterator->node[*word - 'a']);
		iterator = iterator->node[*word - 'a'];
		++word;
	}
	++iterator->prefix;
	++iterator->words;
}

void remove (struct trie *&vertex, const char *word)
{
	if (!*word)
	{
		--vertex->prefix;
		--vertex->words;
		if (!vertex->words)
		{
			delete vertex;
			vertex = 0;
		}
		return;
	}
	remove(vertex->node[*word - 'a'],word + 1);
	--vertex->prefix;
	if (!vertex->prefix)
	{
		delete vertex;
		vertex = 0;
	}
}

inline int words (const struct trie *vertex, const char *word)
{
	while (*word)
	{
		if (!vertex)
			return 0;
		vertex = vertex->node[*word - 'a'];
		++word;
	}
	return vertex->words;
}

inline int prefix (const struct trie *vertex, const char *word)
{
	if (!vertex)
		return 0;
	int length(0);
	while (*word && vertex->node[*word - 'a'])
	{
		vertex = vertex->node[*word - 'a'];
		++word;
		++length;
	}
	return length;
}

int main (void)
{
	std::freopen("trie.in","r",stdin);
	std::freopen("trie.out","w",stdout);
	struct trie *data(0);
	char s [SIZE];
	std::gets(s);
	while (!std::feof(stdin))
	{
		if (*s == '0')
			insert(data,s + 2);
		else if (*s == '1')
			remove(data,s + 2);
		else if (*s == '2')
			std::printf("%d\n",words(data,s + 2));
		else
			std::printf("%d\n",prefix(data,s + 2));
		std::gets(s);
	}
	std::fclose(stdin);
	std::fclose(stdout);
	return 0;
}