#include<fstream>
#include<string.h>
#include<ctype.h>
#include<algorithm>
#include<map>
#include<unordered_map>
#include<array>
#include<unordered_set>
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");
int type;
char str[21];
struct Trie 
{
	int nrprefixe,nrcuv;
	Trie *fiu[26];

	Trie() 
	{
		nrprefixe = nrcuv = 0;
		memset(fiu, 0, sizeof(fiu));
	}
};

Trie *root = new Trie();
void add(string s)
{
	Trie *node = root;
	int i,l = s.size();
	for (i = 0; i < l; i++)
	{
		if (node->fiu[s[i] - 'a'] == 0)
			 node->fiu[s[i] - 'a']=new Trie;
		node->nrprefixe++;
		node = node->fiu[s[i] - 'a'];
		if (i == l - 1)
		{
			node->nrcuv++;
			node->nrprefixe++;
		}
	}
}
void del(string s)
{
	Trie *node = root;
	int i, l = s.size();
	for (i = 0; i < l; i++)
	{
		if (node->fiu[s[i] - 'a'] == NULL)
			break;
		else
		{
			node = node->fiu[s[i] - 'a'];
			node->nrprefixe--;
			if (i == l - 1)
			{
				node->nrcuv--;
			}
		}
	}
}
void findcuvnr(string s)
{
	Trie *node = root;
	int i, l = s.size();
	for (i = 0; i < l; i++)
	{
		if (node->fiu[s[i] - 'a'] == NULL)
		{
			g << 0 << '\n';
			break;
		}
		else
		{
			node = node->fiu[s[i] - 'a'];
			if (i == l - 1)
			{
				g << node->nrcuv << '\n';
				return;
			}
		}
	}
}
void findprefnr(string s)
{
	Trie *node = root;
	int i, l = s.size();
	for (i = 0; i < l; i++)
	{
		if (node->fiu[s[i] - 'a'] == 0)
		{
			g << i-1 << '\n';
			return;
		}
		else
		{
			node = node->fiu[s[i] - 'a'];
			if (node->nrprefixe == 0)
			{
				g << i << '\n';
				return;
			}
		}
		
	}
}
int main()
{
	
	while (f >> type >> str)
	{
		if (type == 0)
			add(str);
		else
			if (type == 1)
				del(str);
			else
				if (type == 2)
					findcuvnr(str);
				else
					findprefnr(str);
	}
	return 0;
}