# include <fstream>
# include <algorithm>
# include <cstring>
# define CH (*s - 'a')
# define NR 50
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");
struct Trie {
    int nr, nrfii;
    Trie *fiu[26];
    Trie () {
        nr=0; nrfii=0;
        memset (fiu, 0, sizeof(fiu));
    }
};

Trie *T= new Trie;

void ins (Trie *nod, char *s) {
    if (*s=='\0') {
        nod->nr ++;
        return;
    }

    if (nod->fiu[CH]==0) {
        nod->fiu[CH]=new Trie;
        nod->nrfii ++;
    }

    ins (nod->fiu[CH], s+1);
}
int del (Trie *nod, char *s) {
    if (*s=='\0') nod->nr --;
    else if (del(nod->fiu[CH], s+1)) {
        nod->fiu[CH]=0;
        nod->nrfii --;
    }

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

int query (Trie *nod, char *s) {
    if (*s=='\0') return nod->nr;
    if (nod->fiu[CH]!=0) return query (nod->fiu[CH], s+1);

    return 0;
}

int prefix (Trie *nod, char *s, int k) {
    if (*s=='\0' || nod->fiu[CH]==0) return k;
    else prefix (nod->fiu[CH], s+1, k+1);
}

char s[NR];

int main ()
{
    while (f.getline(s, NR)) {
        switch (s[0]) {
            case '0' : ins(T, s+2); break;
            case '1' : del(T, s+2); break;
            case '2' : g<<query(T, s+2)<<"\n"; break;
            case '3' : g<<prefix(T, s+2, 0)<<"\n"; break;
        }
    }

    return 0;
}