#include <fstream>
#include <vector>
#include <algorithm>
#include <stack>

#define idx (s[i] - 'a')

using namespace std;

class Trie{
	
	vector<Trie*> letter;
	int words;
	int childs;
	
public:
	
	Trie(){
		letter.resize(26);				
		words = 0;
		childs = 0;
	}
	
	void add(string s) {		
		Trie *curent = this;		
		for (int i = 0; i < (int)s.length(); i++){
			if (curent->letter[idx] == 0) {				
				curent->letter[idx] = new Trie;
				curent->childs++;				
			}		
			curent = curent->letter[idx];	
		}
		curent->words++;			
	}	
	
	void rem(string s) {
		stack<Trie*> st;		
		Trie *curent = this;
		char a;
		for (int i = 0; i < (int)s.length(); i++){
			st.push(curent);
			curent = curent->letter[idx];
			a = s[i];
		}
		st.push(curent);	
		st.top()->words--;
		while (st.top()->words == 0 && st.top()->childs == 0){
				Trie *aux = st.top();
				st.pop();
				delete aux;
		}		
	}
	
	int times(string s){
		Trie *prev, *curent = this;
		for (int i = 0; i < (int)s.length(); i++){
			prev = curent;
			curent = curent->letter[idx];
		}		
		return prev->words;		
	}
	
	int longestPrefix(string s) {
		Trie *curent = this;
		int length = 0;
		for (int i = 0; i < (int)s.length() && curent; i++){
			if ( curent->letter[idx] != 0 ) length = i + 1;
			curent = curent->letter[idx];
		}	
		return length;		
	}
	
};

int main(){
	string s;
	int op;
	
	Trie *t = new Trie();
	
	ifstream fin("trie.in");
	ofstream fout("trie.out");
	
	fin >> op >> s;
	
	do {
		
		if (op == 0)
			t->add(s);
		if (op == 1)
			t->rem(s);
		if (op == 2){
			int a = t->times(s);
			fout << a << '\n';
		}
		if (op == 3)
			fout << t->longestPrefix(s) << '\n';
	
	}while ( fin >> op >> s);
	
	//delete t;
	
	return 0;
}