#include <cstdio>
#include <cstring>

const int MAX_N = 20;
const int SIGMA = 26;

class Trie {
public:
  int words;
  int sons;
  Trie* edges[1 + SIGMA];

  Trie() {
    words = sons = 0;
    for (int i = 1; i <= SIGMA; i++) {
      edges[i] = NULL;
    }
  }

  void addWord(char s[], int pos, int length) {
    if (pos == length) {
      words++;
    } else {
      char first = s[pos];
      if (edges[first - 'a' + 1] == NULL) {
        edges[first - 'a' + 1] = new Trie;
        sons++;
      }
      edges[first - 'a' + 1]->addWord(s, pos + 1, length);
    }
  }

  bool deleteWord(Trie* t, char s[], int pos, int length) {
    if (pos == length) {
      words--;
    } else {
      char first = s[pos];
      bool aux = edges[first - 'a' + 1]->deleteWord(t, s, pos + 1, length);
      if (aux == 1) {
        sons--;
        edges[first - 'a' + 1] = NULL;
      }
    }
    if (sons == 0 && words == 0 && this != t) {
      delete this;
      return 1;
    }
    return 0;
  }

  int countWords(char s[], int length) {
    Trie* aux = this;
    for (int i = 0; i < length; ++i) {
      char k = s[i];
      if (aux->edges[k - 'a' + 1] == NULL) {
        return 0;
      }
      aux = aux->edges[k - 'a' + 1];
    }
    return aux->words;
  }

  int prefixes(char s[], int length) {
    Trie* aux = this;
    for (int i = 0; i < length; i++) {
      char k = s[i];
      if (aux->edges[k - 'a' + 1] == NULL) {
        return i;
      }
      aux = aux->edges[k - 'a' + 1];
    }
  }
};

int main() {
  freopen ("trie.in", "r", stdin);
  freopen ("trie.out", "w", stdout);

  int type;
  Trie* t;
  t = new Trie;
  char s[5 + MAX_N];

  while (scanf("%d", &type) != EOF) {
    getc(stdin);
    scanf("%s", s);
    int length = strlen(s);
    if (type == 0) {
      t->addWord(s, 0, length);
    } else if (type == 1) {
      bool aux = t->deleteWord(t, s, 0, length);
    } else if (type == 2) {
      printf("%d\n", t->countWords(s, length));
    } else if (type == 3) {
      printf("%d\n", t->prefixes(s, length));
    }
  }
  return 0;
}