#include <cstring>
#include <fstream>

#define CH (*s - 'a')

using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
struct Trie
{
	int cnt, nrfii;
	Trie *fiu[ 26 ];

	Trie() {
		cnt = nrfii = 0;
		memset( fiu, 0, sizeof( fiu ) );
	}
} *T = new Trie;
char cuv[30];
void ins(Trie *nod, char *s)
{
	if(!*s)
    {
		nod->cnt++;
        return;
	}

	if(nod->fiu[CH]==0)
    {
		nod->fiu[CH]=new Trie;
		nod->nrfii++;
	}

	ins(nod->fiu[CH],s+1);
}

int del(Trie *nod, char *s)
{
	if(!*s) nod->cnt--;
	else if(del(nod->fiu[CH],s+1))
    {
        nod->fiu[CH]=0;
        nod->nrfii--;
    }
	if(nod->cnt==0&&nod->nrfii==0&&nod!=T)
	{
		delete nod;
        return 1;
	}
	return 0;
}

int que(Trie *nod, char *s)
{
	if(!*s) return nod->cnt;
	if(nod->fiu[CH])
		return que(nod->fiu[CH],s+1);
	return 0;
}

int pre(Trie *nod, char *s, int k)
{
	if(!*s||nod->fiu[CH]==0) return k;
	return pre(nod->fiu[CH],s+1,k+1);
}

int main() {

    fin.getline(cuv,30);
	while(!fin.eof())
    {
		switch(cuv[0])
		{
			case '0': ins( T, cuv+2 ); break;
			case '1': del( T, cuv+2 ); break;
			case '2': fout<<que( T, cuv+2 )<<'\n'; break;
			case '3': fout<<pre( T, cuv+2, 0 )<<'\n'; break;
		}
		fin.getline(cuv,30);
	}
	return 0;
}