#include <bits/stdc++.h>
 
using namespace std;
 
ifstream fin("trie.in");
ofstream fout("trie.out");
 
const int SIGMA = 26;
 
char s[100];
 
struct Trie
{
    Trie* next[SIGMA] = {};
    int wordsEndHere=0;
    int wordsContained=0;
};
 
Trie *root;
 
void AddWord(Trie *node, char *word)
{
    node->wordsContained++;
    if(*word=='\0')
        {
            node->wordsEndHere++;
            return;
        }
    int nextIndex = *word - 'a';
    if(node->next[nextIndex]==NULL)
        node->next[nextIndex] = new Trie;
    AddWord(node->next[nextIndex],word+1);
}
 
void DeleteWord(Trie *node, char *word)
{
    node->wordsContained--;
    if(*word=='\0')
        {
            node->wordsEndHere--;
            return;
        }
    int nextIndex = *word - 'a';
    DeleteWord(node->next[nextIndex],word+1);
    if(node->next[nextIndex]->wordsContained==0)
        {
            delete node->next[nextIndex];
            node->next[nextIndex]=NULL;
        }
}
 
int FreqTrie(Trie *node, char *word)
{
    if(*word=='\0')
        return node->wordsEndHere;
    int nextIndex = *word - 'a';
    if(node->next[nextIndex]==NULL)
        return 0;
    return FreqTrie(node->next[nextIndex],word+1);
}
 
int LongestPrefix(Trie *node, char *word)
{
    if(*word=='\0')
            return 0;
    int nextIndex = *word - 'a';
    if(node->next[nextIndex]==NULL)
        return 0;
    return 1 + LongestPrefix(node->next[nextIndex],word+1);
}
 
int main()
{
    root = new Trie;
    while(fin.getline(s,SIGMA))
        {
            switch(s[0])
                {
                case '0':
                    {
                        AddWord(root,s+2);
                        break;
                    }
                case '1':
                    {
                        DeleteWord(root,s+2);
                        break;
                    }
                case '2':
                    {
                        fout<<FreqTrie(root,s+2)<<'\n';
                        break;
                    }
                default:
                    {
                        fout<<LongestPrefix(root,s+2)<<'\n';
                        break;
                    }
                }
        }
}