#include <bits/stdc++.h>

using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");
typedef struct nod{
    struct nod *fiu[26]; int terminal, nrf;
} 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->nrf = 0;
        T->terminal = 0;
        adauga(T, p);
    }
    else
    {
        T->nrf++;
        if(*p == '\0')T->terminal ++;
        else adauga(T->fiu[*p - 'a'], p + 1);
    }
}
void sterge(TRIE &T, char *p)
{
    int x = *p - 'a';
    T->nrf--;
    if(*p == '\0')
        T -> terminal--;
    else sterge(T->fiu[*p - 'a'], p + 1);
}
int nrapr(TRIE &T, char *p)
{
    int x = *p - 'a';
    if(*p == '\0')return T->terminal;
    if(T->fiu[x] == 0)return 0;
    return nrapr(T->fiu[x], p + 1);
}
int prefmax(TRIE &T, char *p)
{
    int x = *p - 'a';
    if(*p == '\0')return 0;
    if(!T->fiu[x])return 0;
    return 1 + prefmax(T->fiu[x], 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 << nrapr(T, cuv) << '\n';
        else fout << prefmax(T, cuv) << '\n';
    }
    return 0;
}