#include<cstdio>
#include<cstring>
#define CHR *str-'a'
using namespace std;
struct Trie
{
	int cnt,nrfii;
	Trie *fiu[26];
	Trie()
	{
		cnt=nrfii=0;
		memset(fiu,0,sizeof(fiu));
	}
};
char line[35];
void solve(),add(Trie*,char*);
int query(Trie*,char*),prefix(Trie*,char*,int),del(Trie*,char*);
Trie *T = new Trie;

int main()
{
	solve();
	return 0;
}
void solve()
{
	freopen("trie.in","r",stdin);
	freopen("trie.out","w",stdout);
	
	fgets(line, 32, stdin);
	while(!feof(stdin))
	{
		switch(line[0])
		{
			case '0': add(T,line+2);break;
			case '1': del(T,line+2); break;
			case '2': printf("%d\n",query(T,line+2));break;
			case '3': printf("%d\n",prefix(T,line+2,0));break;
		}
		
		fgets(line,32,stdin);
	}
}
void add(Trie *nod,char* str)
{
	if(*str == '\n') { nod->cnt++; return; }
	if(!nod->fiu[CHR])
	{
		nod->fiu[CHR]=new Trie;
		nod->nrfii++;
	}
	add(nod->fiu[CHR],str+1);
}
int del(Trie *nod,char *str)
{
	if(*str == '\n') nod->cnt--;
	else if(del(nod->fiu[CHR],str+1))
	{
		nod->fiu[CHR]=0;
		nod->nrfii--;
	}
	
	if(nod->nrfii || nod->cnt || nod == T) return 0;
	delete nod;	return 1; 
}
int query(Trie *nod,char *str)
{
	if(*str == '\n') return nod->cnt;
	if(nod->fiu[CHR])return query(nod->fiu[CHR],str+1);
	return 0;
}
int prefix(Trie *nod,char *str,int k)
{
	if(*str=='\n'||!nod->fiu[CHR]) return k;
	return prefix(nod->fiu[CHR],str+1,k+1);
}