#include <iostream>
#include <fstream>
#include <cstring>
#include <iomanip>
#include <cstdio>
#define CH (*s-'a')
using namespace std;

char line[30];
struct Trie{
    int nrfii,cuv;
    Trie *fii[30];

    Trie()
    {
        nrfii=cuv=0;
        memset(fii,0,sizeof(fii));
    }
};

Trie *T= new Trie;
void add(Trie *nod,char *s)
{
    if(*s=='\0')
    {
        nod->cuv++;
        return;
    }

    if(nod->fii[*s-'a'] == 0)
    {
        nod->fii[CH]=new Trie;
        nod->nrfii++;
    }
    add(nod->fii[CH],s+1);
}
int del(Trie *nod, char *s)
{
    if(*s=='\0')
        nod->cuv--;
    else if(del(nod->fii[CH],s+1))
    {
        nod->fii[CH]=0;
        nod->nrfii--;
    }

    if(nod->cuv == 0 && nod->nrfii ==0 && nod!=T)
    {
        delete nod; return 1;
    }

    return 0;
}
int que(Trie *nod,char *s)
{
    if(*s=='\0')
        return nod->cuv;

    if(nod->fii[CH])
        return que(nod->fii[CH],s+1);
    return 0;
}

int pre(Trie *nod,char *s,int k)
{
    if(*s=='\0' || nod->fii[CH]==0)
        return k;
    return pre(nod->fii[CH],s+1,k+1);
}
int main()
{
    ifstream fin("trie.in");
    ofstream fout("trie.out");
    int n;
    while(fin>>n)
    {
        fin.getline(line,25);
        switch(n){
            case 0: add(T,line+1);break;
            case 1: del(T,line+1);break;
            case 2: fout<<que(T,line+1)<<'\n';break;
            case 3: fout<<pre(T,line+1,0)<<'\n';break;
        }
    }
    return 0;
}