#include <fstream>
#include <string>
#include <algorithm>
#include <cassert>

struct TrieNode
{
	int leaf;
	int passing;
	TrieNode* next[26];
	TrieNode();
	void AddWord(const char*);
	void RemWord(const char*);
	int ComputeAppearances(const char*);
	int ComputeMaxSubstr(const char*);
};

TrieNode::TrieNode() : leaf(0), passing(0)
{
	for (int i = 0; i < 26; ++i)
		next[i] = 0;
}

void TrieNode::AddWord(const char* word)
{
	if (!*word){
		++leaf;
		return;
	}
	int idx = *word - 'a';
	TrieNode* nextNode = next[idx];
	if (!nextNode) {
		nextNode = new TrieNode();
		next[idx] = nextNode;
	}
	++nextNode->passing;
	nextNode->AddWord(word + 1);
}

void TrieNode::RemWord(const char* word)
{
	if (!*word) {
		--leaf;
		return;
	}
	int idx = *word - 'a';
	TrieNode* nextNode = next[idx];
	assert(nextNode);
	--nextNode->passing;
	nextNode->RemWord(word + 1);
}

int TrieNode::ComputeAppearances(const char* word)
{
	if (!*word)
		return leaf;
	TrieNode* nextNode =  next[*word - 'a'];
	if (!nextNode)
		return 0;
	return nextNode->ComputeAppearances(word + 1);
}

int TrieNode::ComputeMaxSubstr(const char* word)
{
	if (!*word){
		return passing ? 0 : -1;
	}
	TrieNode* nextNode =  next[*word - 'a'];
	if (!nextNode)
		return 0;
	if (!nextNode->passing)
		return 0;
	return 1 + nextNode->ComputeMaxSubstr(word + 1);	
}

int main()
{
	char line[30];
	std::ifstream fin("trie.in");
	std::ofstream fout("trie.out");
	TrieNode* tn = new TrieNode();
	while (fin.getline(line, 30)) {
		int ret;
		switch (*line) {
			case '0':
				tn->AddWord(line+2);
				break;
			case '1':
				tn->RemWord(line+2);
				break;
			case '2':
				ret = tn->ComputeAppearances(line + 2);
				fout << ret << "\n";
				break;
			case '3':
				fout << tn->ComputeMaxSubstr(line + 2) << "\n";
				break;	
		}
	}
	fin.close();
	fout.close();
	return 0;
}