#include <bits/stdc++.h>

#define CH(s) (*s - 'a')

using namespace std;

ifstream f("trie.in");
ofstream g("trie.out");

struct Trie
{
	int cnt, nch;
	Trie *child[26];

	Trie() {
		cnt=nch=0;
		memset(child,0,sizeof(child));
	}
};

Trie *T = new Trie;

void i(Trie *t,char *s)
{
	if(strlen(s)==0) { t->cnt++; return; }

	if(t->child[CH(s)]==0)
		t->child[CH(s)]=new Trie, t->nch++;
	i(t->child[CH(s)],s+1);
}

int d(Trie *t,char *s)
{
	if(strlen(s)==0) t->cnt--;
	else if(d(t->child[CH(s)],s+1))
			t->child[CH(s)]=0,t->nch--;

	if(t->cnt==0 && t->nch==0 && t!=T ) { delete t; return 1; }
	return 0;
}

int q(Trie *t,char *s)
{
	if(strlen(s)==0) return t->cnt;
	if(t->child[CH(s)])
		return q(t->child[CH(s)],s+1);
	return 0;
}

int k=0;
int p(Trie *t,char *s)
{
	if(strlen(s)==0 || t->child[CH(s)]==0) return k;
	return k++,p(t->child[CH(s)],s+1);
}

int main() {
	char s[32];

    f.get(s,32);

	while(!f.eof())
    {
		switch(s[0])
		{
			case '0':i(T,s+2); break;
			case '1':d(T,s+2); break;
			case '2':g<<q(T,s+2)<<'\n'; break;
			case '3':k=0,g<<p(T,s+2)<<'\n'; break;
		}
		f.get();f.get(s,32);
	}
	return 0;
}