#include<fstream>
#include<string>
using namespace std;
 
int op,N,c,j,cuvant,ok;
char cuv[30];
 
struct Trie { int inf; Trie *fiu[30]; } *R,*nou;
 
void add (Trie *&nod, int i)
{
    c=(int)(cuv[i]-'a');
 
    if(i==N)
    {
        nod->inf++;
        return ;
    }
     
    if(nod->fiu[c]==NULL)    
    {
        nou=new Trie;
        nou->inf=0;
        for(j=0;j<26;j++)
            nou->fiu[j]=NULL;
        nod->fiu[c]=nou;
    }
         
    add(nod->fiu[c],i+1);
}
 
void del (Trie *&nod, int i)
{
    int c=(int)(cuv[i]-'a');
     
    if(i==N) nod->inf--;
     
        else del(nod->fiu[c],i+1);
     
    if(i!=N)
        if(ok) nod->fiu[c]=NULL;
            else return;
     
    if(nod==R) return;
     
    ok=0;
    if(nod->inf==0)
    {
        ok=1;
         
        for(j=0;j<26&&ok;j++)
            if(nod->fiu[j]) ok=0;
         
        if(ok)
        {
            delete nod;
            nod=NULL;
        }
    }
}
 
int find (Trie *nod, int i)
{
    c=(int)(cuv[i]-'a');
     
    if(i==N) return nod->inf;
    if(nod->fiu[c]) return find(nod->fiu[c],i+1);
    return 0;
}
 
int query (Trie *nod, int i)
{
    c=(int)(cuv[i]-'a');
    if(i==N) return N;
    if(nod->fiu[c]) 
        return query(nod->fiu[c],i+1);
    return i;
}
 
int main()
{
    ifstream f("trie.in");
    ofstream g("trie.out");
     
    R=new Trie;
    R->inf=0;
    for(j=0;j<26;j++)
        R->fiu[j]=NULL;
     
    while(f>>op)
    {
        cuvant++;
        for(j=0;j<30;j++)
            cuv[j]='\0';
        f>>cuv;
        N=strlen(cuv);
         
        switch(op)
        {
        case 0: add(R,0); break;
        case 1: del(R,0); break;
        case 2: g<<find(R,0)<<'\n'; break;
        case 3: g<<query(R,0)<<'\n'; break;
        }
    }
     
    f.close();
    g.close();
    return 0;
}