#include<fstream>
#include<string.h>
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");
int x;
char cuv[20]; 
class Trie
{ public:
 int nr_cuvinte;
 Trie *fii[26];
  
  Trie()
    {nr_cuvinte=0;
	 memset(fii,0,sizeof(fii));
    }
  int empty()
   {
   	for(int i=0;i<=25;i++)
   		if(fii[i]!=0)
   			return 0;
   		return 1;
   }
	
}*rad=new Trie();
void ad_cuv(int x,Trie *q,const char *w)
{  
	if(x==strlen(w))
	{
		++q->nr_cuvinte;
		return;
	}
	if(q->fii[w[x]-'a']==0)
	{
		q->fii[w[x]-'a']=new Trie();
		//++q->sons;
	}
	ad_cuv(x+1,q->fii[w[x]-'a'],w);
}
bool del_cuv(int poz,Trie *q,const char *w)
{ 
	if(poz==strlen(w))
	{--q->nr_cuvinte;
	  if(q->nr_cuvinte==0&&(q->empty()))
	  {   delete q;
	      return 1;
	  }
	
	   return 0;
	 }
	
	if(del_cuv(poz+1,q->fii[w[poz]-'a'],w))
	 {
	 	//--q->sons;
	 	q->fii[w[poz]-'a']=0;
	 }
	 if((q->empty())&&q!=rad&&(q->nr_cuvinte==0))
	 {
	 	delete q;
	 	return 1;
	 }
  return 0;
}
int print_nrcuv (int x,Trie *q,const char *w)
{
	if(x==strlen(w))
		return q->nr_cuvinte;
	if(q->fii[w[x]-'a']!=0)
		return print_nrcuv(x+1,q->fii[w[x]-'a'],w);
	return 0;
}
int prefix_maxim(int x,Trie *q,const char *w)
{
	if(q->fii[w[x]-'a']!=0&&x<strlen(w))
		return prefix_maxim(x+1,q->fii[w[x]-'a'],w);
	if(x<strlen(w)) return x;
	else return strlen(w);
}
int main()
{
   while(f>>x>>cuv)
   {   
		switch(x)
		{
			case 0:
			ad_cuv(0,rad,cuv);
			break;
			case 1:
			del_cuv(0,rad,cuv);
			break;
			case 2:
			g<<print_nrcuv(0,rad,cuv)<<'\n';
			break;
            case 3:
            g<<prefix_maxim(0,rad,cuv)<<'\n';
            break;
        }
	}
	f.close();
	g.close();
	return 0;
}