#include <cstring>
#include <cstdlib>
#include <iostream>
#include <vector>
using namespace std;


// int to char
inline int i2c(char c){ return c-'a'; }
 
// Trie structure
struct Trie{
    int n_words;
    int n_prefixes; 
    vector<Trie*> children;
};

Trie *root;


Trie *new_trie(){
  Trie* node = new Trie;
  node->n_words = 0;
  node->n_prefixes = 0;
  node->children.resize(26,NULL);
  return node;
}
 
void add(Trie* trie, char *w){
  if(*w == '\0')
    trie->n_words++;
  else{
    if(trie->children[i2c(*w)] == NULL){
        trie->children[i2c(*w)] = new_trie();
        trie->n_prefixes++;
    }
    add(trie->children[i2c(*w)], w+1);
  }
}
 
int del(Trie* trie, char *w){
  if(*w == '\0'){
    trie->n_words--;
  }
  else{
    int res = del(trie->children[i2c(*w)], w+1);
    if(res == 1){
      trie->children[i2c(*w)] = NULL;
      trie->n_prefixes--;
    }
  }
  if(trie->n_words == 0 && trie->n_prefixes == 0 && trie != root){
    delete trie;
    return 1;
  }
  return 0;
}
 
int prefix(Trie* trie, char *w, int k){
  if(*w == '\0' || trie->children[i2c(*w)] == NULL)
    return k;
  return prefix(trie->children[i2c(*w)], w+1, k+1);
}
 
int find(Trie* trie, char *w){
  if(*w == '\0')
    return trie->n_words;
  if(trie->children[i2c(*w)] != NULL)
    return find(trie->children[i2c(*w)], w+1);
  return 0;
}

int main(){
 
  freopen("trie.in", "r", stdin);
  freopen("trie.out", "w", stdout);
 
  root = new_trie();
 
  int op;
  char s[21];
  while(scanf("%d %s\n", &op, s) != EOF){
    if(op == 0){
      add(root, s);
    }
    else if(op == 1){
      del(root,s);
    }
    else if(op == 2){
      printf("%d\n", find(root,s));
    }
    else if(op == 3){
      printf("%d\n", prefix(root,s,0));
    }
  }
 
 
  return 0;
}