#include <cstring>
#include <cstdio>

#include <fstream>
#include <iostream>
#include <string>
#include <vector>
using namespace std;

struct trie {
   int f[26], cnt, nrf;
};

vector<trie> T;
string s;

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

inline void newnode() {
   trie n;
   n.cnt = n.nrf = 0;
   memset(n.f, 0, sizeof(n.f));
   T.push_back(n);
}

inline void ins(int p, int node) {
   if(p == s.size()) {
      ++T[node].cnt;
      ++T[node].nrf;
   }
   else {
      if(T[node].f[s[p] - 'a'] == 0) {
         newnode();
         T[node].f[s[p] - 'a'] = T.size() - 1;
      }
      ins(p + 1, T[node].f[s[p] - 'a']);
      ++T[node].nrf;
   }
}

inline void del(int p, int node) {
   if(p == s.size()) {
      --T[node].cnt;
      --T[node].nrf;
   }
   else {
      if(T[node].f[s[p] - 'a'] == 0) {
         newnode();
         T[node].f[s[p] - 'a'] = T.size() - 1;
      }
      del(p + 1, T[node].f[s[p] - 'a']);
      --T[node].nrf;
   }
}

inline void print_no(int p, int node) {
   if(p == s.size())
      out << T[node].cnt << '\n';
   else if(T[node].f[s[p] - 'a'] == 0)
      out << 0 << '\n';
   else print_no(p + 1, T[node].f[s[p] - 'a']);
}

inline void print_LCP(int p, int node, int sol) {
   if(p == s.size() || T[node].f[s[p]-'a'] == 0 || T[T[node].f[s[p]-'a']].nrf == 0)
      out << sol << '\n';
   else
      print_LCP(p + 1, T[node].f[s[p] - 'a'], sol + 1);
}

int main()
{
    newnode();
    newnode();
    int op;
    in >> op;
    while(!in.eof()) {
      in >> s;
      if(op == 0)
         ins(0, 1);
      if(op == 1)
         del(0, 1);
      if(op == 2)
         print_no(0, 1);
      if(op == 3)
         print_LCP(0, 1, 0);
      in >> op;
    }
    return 0;
}