#include <stdio.h>
#define SIGMA 26
#define Nmax 22
using namespace std;
struct Trie
{
    int cnt,sons;
    Trie *son[SIGMA];
    Trie()
    {
        cnt = sons = 0;
        for(int i=0;i<SIGMA;++i)
            son[i] = 0;
    }
}*nod;
void create_node(Trie *&x)
{
    x = new Trie();
}
void insert(Trie *&x, char *s)
{
    if(*s == 0)
    {
        ++x->cnt;
        return;
    }
    int code = s[0] - 'a';
    if(x->son[ code ] == 0)
    {
        create_node(x->son[code]);
        ++x->sons;
    }
    insert(x->son[code], s+1);
}
void remove(Trie *&x, char *s)
{
    if(*s == 0)
    {
        --x->cnt;
        return;
    }
    int code = s[0] - 'a';

    if(x->son[code] == 0)
        return;

    remove(x->son[code], s+1);
    if(x->son[code]->cnt == 0 && x->son[code]->sons == 0)//daca fiul nodului x nu are alti fii si nu este un final de cuv il stergem
    {
        delete x->son[code];
        x->son[code] = 0;
        --x->sons;
    }
}
int count(Trie *x, char *s)
{
    if(*s == 0)
    {
        return x->cnt;
    }
    int code = s[0] - 'a';
    if(x->son[code] == 0)
    {
        return 0;
    }
    return count(x->son[code],s+1);
}
int maxim(int a,int b)
{
    if(a>=b)
        return a;
    return b;
}
int pref(Trie *x, char *s,int l)
{
    if(x == 0)
        return 0;
    if(*s == 0)
    {
        return l;
    }
    int code = s[0] - 'a';

    if(x->sons || x->cnt)//daca acest nod are mai mult de 2 fii sau pana aici s-a format un cuv atunci l(adancimea) ramane valabila
        return maxim(l, pref(x->son[code], s+1, l+1));
}
void show_node(Trie *x)
{
    printf("%d ",x->cnt);
    for(int i=0;i<SIGMA;++i)
        if(x->son[i])
            printf("%c %d %d\n",char(i+'a'), x->son[i]->cnt, x->son[i]->sons);

    printf("\n");
}
int main()
{
    create_node(nod);

    FILE*f = fopen("trie.in","r");
    FILE*g = fopen("trie.out","w");
    int op,la=0;
    char buf[Nmax];
    while(!feof(f))
    {
        fscanf(f,"%d %s",&op,buf);
        if(feof(f))
            continue;
        switch(op)
        {
            case 0:
                //printf("%s\n",buf);
                insert(nod, buf);
            break;
            case 1:
                remove(nod,buf);
            break;
            case 2:
                fprintf(g,"%d\n",count(nod,buf));
            break;
            case 3:
                fprintf(g,"%d\n",pref(nod,buf,0));
            break;
        }
    }
    //show_node(nod->son['m' - 'a']);
    fclose(f);
    fclose(g);
    return 0;
}