#include <cstring>
#include <iostream>

using namespace std;
struct Trie
{
    int nrfii;
    short unsigned cnt;
    Trie *fii[26];
    Trie()
    {
        nrfii=cnt=0;
        for(int i=0;i<26;i++)fii[i]= NULL;
    }
};

Trie *T = new Trie;
void ins(Trie *nod,char *s)
{
    if(*s=='\n')
    {
        nod->cnt++;return ;
    }
    if(nod->fii[*s-'a']==0)
    {
        nod->fii[*s-'a']= new Trie;
        nod->nrfii++;
    }
    ins(nod->fii[*s-'a'],s+1);
}

int del(Trie *nod,char *s)
{
    if(*s=='\n')
        nod->cnt--;
    else
    {
        if(del(nod->fii[*s-'a'],s+1))
        {
            nod->fii[*s-'a']=NULL;
            nod->nrfii--;
        }
    }
    if(nod->cnt==0 && nod->nrfii==0 && nod!=T)
    {
        delete nod;
        return 1;
    }
    return 0;
}

int apar(Trie *nod,char *s)
{
    if(*s=='\n')
        return nod->cnt;
    if(nod->fii[*s-'a'])
        return apar(nod->fii[*s-'a'],s+1);
    return 0;
}

int pre(Trie *nod,char *s,int k)
{
    if(*s=='\n' || nod->fii[*s-'a']==0)
        return k;
    return pre(nod->fii[*s-'a'],s+1,k+1);
}

int main()
{
    freopen("trie.in","r",stdin);
    freopen("trie.out","w",stdout);
    char linie[24];
    fgets(linie,24,stdin);
    while(!feof(stdin))
    {
        switch(linie[0])
        {
        case '0':
            ins(T,linie+2);
            break;
        case '1':
            del(T,linie+2);
            break;
        case '2':printf("%d\n",apar(T,linie+2));break;
        case '3':
            printf("%d\n",pre(T,linie+2,0));
            break;
        }
        fgets(linie,24,stdin);
    }
    return 0;
}