#include <bits/stdc++.h>

using namespace std;
ifstream fin("trie.in");
ofstream fout("trie.out");

struct trieNode{
    int wordsContained=0, wordsEnd=0;
    trieNode *next[26];
};

void addTrie(trieNode *node, char *word){
    node->wordsContained++;
    if(*word==0){
        node->wordsEnd++;
        return;
    }
    int nextIndex=word[0]-'a';
    if(node->next[nextIndex]==NULL)
        node->next[nextIndex]=new trieNode;
    addTrie(node->next[nextIndex],word+1);
}

void removeTrie(trieNode *node, char *word){
    node->wordsContained--;
    if(*word==0){
        node->wordsEnd--;
        return;
    }
    int nextIndex=word[0]-'a';
    removeTrie(node->next[nextIndex],word+1);
    if(node->next[nextIndex]->wordsContained==0){
        trieNode *p=node->next[nextIndex];
        node->next[nextIndex]=NULL;
        delete p;
    }
}

int appTrie(trieNode *node, char *word){
    if(*word==0){
        return node->wordsEnd;
    }
    int nextIndex=word[0]-'a';
    if(node->next[nextIndex]==NULL)
        return 0;
    return appTrie(node->next[nextIndex],word+1);
}

int longestCommonPrefix(trieNode *node, char *word){
    if(*word==0)
        return 0;
    int nextIndex=word[0]-'a';
    if(node->next[nextIndex]==NULL)
        return 0;
    return 1+longestCommonPrefix(node->next[nextIndex],word+1);
}

int main()
{
    int cerinta;
    char word[25]={};
    trieNode *start=new trieNode;
    while(fin>>cerinta>>word){
        if(cerinta==0){
            addTrie(start,word);
        }
        else if(cerinta==1){
            removeTrie(start,word);
        }
        else if(cerinta==2){
            fout<<appTrie(start,word)<<'\n';
        }
        else if(cerinta==3){
            fout<<longestCommonPrefix(start,word)<<'\n';
        }
    }

    fin.close();
    fout.close();
    return 0;
}