#include <bits/stdc++.h>

using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
typedef struct nod{struct nod *fiu[26]; int terminal;} NOD, *TRIE;
TRIE T = NULL;
int v, maxim;
char cuv[25], *p1;
void adauga(TRIE &T, char *p)
{
    if(T == 0)
    {
        T = new NOD;
        for(int i = 0; i <= 25; ++i)T->fiu[i] = 0;
        T->terminal = 0;
        adauga(T, p);
    }
    else if(*p == '\0')T->terminal ++;
    else adauga(T->fiu[*p - 'a'], p + 1);
}
void sterge(TRIE &T, char *p)
{
    if(*p == '\0')
        T -> terminal--;
    else sterge(T->fiu[*p - 'a'], p + 1);
    bool ok = 1;
    for(int i = 0; i <= 25; ++i)
        if(T->fiu[i] != 0)ok = 0;
    if(ok == 1)
    {
        T = 0;
        delete(T);
    }
}
int verif(TRIE &T, char *p)
{
    if(*p == '\0')return T->terminal;
    return verif(T->fiu[*p - 'a'], p + 1);
}
int prefmax(TRIE &T, char *p)
{
    if(*p == '\0')return 0;
    if(T->fiu[*p - 'a'] == 0)return 0;
    return 1 + prefmax(T->fiu[*p - 'a'], p + 1);
}
int main()
{
    while(fin >> v)
    {
        fin >> cuv;
        if(v == 0)adauga(T, cuv);
        else if(v == 1)sterge(T, cuv);
        else if(v == 2)fout << verif(T, cuv) << '\n';
        else fout << prefmax(T, cuv) << '\n';
    }
    return 0;
}