# 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 {
    Trie *fiu[26];
    int nrfii, cnt;
    Trie () {
        memset (fiu, 0, sizeof(fiu));
        nrfii=0; cnt=0;
    }
};
Trie *T=new Trie;
char s[NR];
void ins (Trie *nod, char *s) {
    if (*s=='\0') {
        nod->cnt ++;
        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->cnt --;
    else if (del(nod->fiu[CH], s+1)) {
        nod->fiu[CH]=0;
        nod->nrfii --;
    }

    if (nod->cnt==0 && nod->nrfii==0 && nod!=T) {
        delete nod;
        return 1;
    }
    return 0;
}
int query (Trie *nod, char *s) {
    if (*s=='\0') return nod->cnt;
    if (nod->fiu[CH]) 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 return prefix (nod->fiu[CH], s+1, k+1);
}
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;
}