#include<fstream>
using namespace std;

const int ALPHABET_SIZE = 26;

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

struct TrieNode
{
    struct TrieNode *children[ALPHABET_SIZE];
    int apparitions = 0;
    struct TrieNode *parent;
};

struct TrieNode *getNode(void)
{
    struct TrieNode *pNode =  new TrieNode;

    pNode->apparitions = 0;

    for (int i = 0; i < ALPHABET_SIZE; i++)
        pNode->children[i] = NULL;

    return pNode;
}

void insert(struct TrieNode *root, string key)
{
    for (unsigned int i = 0; i < key.length(); i++)
    {
        int index = key[i] - 'a';
        if (!root->children[index]){
            root->children[index] = getNode();
            root->children[index]->parent = root;
        }
        root = root->children[index];
    }

    root->apparitions++;
}

int getNumberOfApparitions(struct TrieNode *root, string key)
{
    for (unsigned int i = 0; i < key.length(); i++)
    {
        int index = key[i] - 'a';
        if (!root->children[index])
            return 0;

        root = root->children[index];
    }

    return root->apparitions;
}

bool checkIfNodeHasChildren(struct TrieNode *root){
    for (unsigned int i = 0; i < ALPHABET_SIZE; i++)
        if(root->children[i] != NULL){
            return true;
        }
    return false;
}

void deleteNode(struct TrieNode *root, string key)
{
    for (unsigned int i = 0; i < key.length(); i++)
    {
        int index = key[i] - 'a';
        root = root->children[index];
    }

    root->apparitions--;
    int keyLength = key.length()-1;
    while(!checkIfNodeHasChildren(root) && root->apparitions == 0){
        root = root->parent;
        root->children[key[keyLength] - 'a'] = NULL;
        keyLength--;
    }
}

unsigned int getLongestPrefix(struct TrieNode *root, string key)
{
    unsigned int i = 0;
    for(i = 0; i < key.length(); i++)
    {
        int index = key[i] - 'a';
        if (!root->children[index])
            return i;

        root = root->children[index];
    }
    return i;
}

int main()
{
    int operation;
    string word, substring;
    struct TrieNode *root = getNode();

    while(fin>>operation>>word){
        if(operation == 0){
            insert(root, word);
        }

        if(operation == 1){
            deleteNode(root, word);
        }

        if(operation == 2){
            fout<<getNumberOfApparitions(root, word)<<endl;
        }

        if(operation == 3){
            fout<<getLongestPrefix(root, word)<<endl;
        }
    }

    return 0;
}