#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define eb emplace_back
#define pb push_back
#define qwerty1 first
#define qwerty2 second
#define qwerty3 -> first
#define qwerty4 -> second
#define umap unordered_map
#define uset unordered_set
#define pii pair < int , int >
#define pq priority_queue
#define dbg(x) cerr << #x << ": " << x << '\n'

using namespace std;

const int N = 1e5 + 10;
const int M = 1e9 + 7;
const ld PI = acos(-1);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ifstream f ("trie.in");
ofstream g ("trie.out");

struct Trie
{
    Trie *alp[200];
    int cnt , let;

    Trie()
    {
        cnt = let = 0;
        memset(alp , 0 , sizeof(alp));
    }
};

Trie *T = new Trie;
char line[30];

void add(Trie *&nod , char *ch)
{

    if(*ch == '\0')
        return ++nod -> cnt , void();

    if(nod -> alp[*ch] == NULL)
        ++nod -> let , nod -> alp[*ch] = new Trie;

    add(nod -> alp[*ch] , ch + 1);
}

bool del(Trie *&nod , char *ch)
{

    if(*ch == '\0')
    {
        --nod -> cnt;

        if(!nod -> cnt && !nod -> let && nod != T)
            return delete nod , 1;

        return 0;
    }

    bool ok = del(nod -> alp[*ch] , ch + 1);

    if(ok)
    {
        nod -> alp[*ch] = NULL;
        --nod -> let;

        if(!nod -> let && nod != T)
            return delete nod , 1;
    }

    return 0;
}

void cnt(Trie *nod , char *ch)
{
    if(*ch == '\0')
        return g << nod -> cnt << '\n' , void();

    if(nod -> alp[*ch] == NULL)
        return g << 0 << '\n' , void();

    cnt(nod -> alp[*ch] , ch + 1);
}

void pref(Trie *nod , char *ch , int ans)
{
    if(*ch == '\0')
        return g << ans << '\n' , void();

    if(nod -> alp[*ch] == NULL)
        return g << ans << '\n' , void();

    pref(nod -> alp[*ch] , ch + 1 , ans + 1);
}

signed main()
{
	#ifndef ONLINE_JUDGE
       // freopen("trie.in" , "r" , stdin) , freopen("trie.out" , "w" , stdout);
        ios_base::sync_with_stdio(false) , f.tie(0) , cout.tie(0);
	#endif

    while(f.getline(line , 20))
    {
        if(*line == '0')
            add(T , line + 2);
        else if(*line == '1')
            del(T , line + 2);
        else if(*line == '2')
            cnt(T , line + 2);
        else if(*line == '3')
            pref(T , line + 2 , 0);
    }


    return 0;
}