#include <stdio.h>
#include <string.h>
#include <vector>


using namespace std;
#define maxn 570000
vector < vector< int > > trie;
int nr[maxn];
int nr2[maxn];
int help[26];
int nr_nodes, rez;



void add( char *sir, int where, int how_muci)
{
	//nr[ where] += how_muci;
	nr2[ where] += how_muci;
	if( sir[0] > 'z' || sir[0] < 'a') {nr[ where] += how_muci;return;}
	
	
	if( trie[ where ][ sir[0] - 'a' ] == -1)
	{
		vector< int > a;
		for( int i = 1; i <= 26; ++i) a.push_back(-1);
		trie.push_back(a);
		
		trie[ where ][ sir[0] - 'a' ] = ++nr_nodes;
	}
	add( sir + 1, trie[ where ][ sir[0] - 'a' ], how_muci);
}
void deleter( char *sir, int where)
{
	
	nr2[ where]--;
	if( sir[0] > 'z' || sir[0] < 'a') {
		nr[ where]--;
		if( nr2[where] == 0) trie[where].erase( trie[where].begin(), trie[where].end());
		return;
	}
	
	int x = trie[ where ][ sir[0] - 'a' ];
	if( nr2[where] == 0) trie[where].erase( trie[where].begin(), trie[where].end());

	deleter( sir + 1, x);
}

int cate( char *sir, int where)
{
	
	
	if( sir[0] > 'z' || sir[0] < 'a') return nr[ where];
	
	if( trie[ where ][ sir[0] - 'a' ] == -1)
	{
		return 0;
	}
	return cate( sir + 1, trie[ where ][ sir[0] - 'a' ]);
}

int pref( char *sir, int where, int sol)
{
	if( nr2[where ] == 0)
	{
		if( sol != 0)
			return sol-1;
		return 0;
	}
	if( trie[ where ][ sir[0] - 'a' ] == -1)
		return sol;
	return pref( sir + 1, trie[ where ][ sir[0] - 'a' ], sol + 1);
}

int main()
{
	freopen("trie.in","r",stdin);
	freopen("trie.out","w",stdout);
	char sir[22];
	int n;
	vector< int > a;
	for( int i = 1; i <= 26; ++i) a.push_back(-1);
	trie.push_back(a);
	memset(sir,0,sizeof(sir));
	while( scanf("%d %s",&n, sir) == 2)
	{
		if( n == 0)
			add( sir, 0, 1);
		if( n == 1)
			deleter( sir, 0);
		if( n == 2)
			printf("%d\n",cate( sir, 0));
		if( n == 3)
			printf("%d\n",pref( sir, 0, 0));
		
	}


	return 0;
}