#include <iostream>
#include <fstream>
#include <string>

using namespace std;

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

int cn(char c){
	return (c-'a');
}

struct trie{
	trie *son[26];
	int v = 0, k = 0;
	void iadd(const string &s, int ind=0){
		int a = cn(s[ind]);
		if(!son[a]){
			k++;
			son[a] = new trie();
		}
		if(ind == s.size()-1){
			son[a]->v++;
		}else{
			son[a]->iadd(s, ind+1);
		}
	}
	void iraze(const string &s, int ind=0){
		int a = cn(s[ind]);
		if(ind == s.size()-1){
			son[a]->v--;
		}else{
			son[a]->iraze(s, ind+1);
		}
		
		if(son[a]->v == 0 && son[a]->k == 0){
			delete son[a];
			son[a] = NULL;
			k--;
		}
	}
	int ifind(const string &s, int ind=0){
		int a = cn(s[ind]);
		if(ind == s.size()-1){
			return son[a]->v;
		}else{
			return son[a]->ifind(s, ind+1);
		}
	}
	int iprefix(const string &s, int ind=0){
		int a = cn(s[ind]);
		if(son[a] && ind+1<s.size()){
			return son[a]->iprefix(s, ind+1);
		}else{
			return ind;
		}
	}
};
trie *root = new trie();

int main(){
	//ios_base::sync_with_stdio(false);
	int op;
	string s;
	while(fin >> op >> s){
		if(op == 0){
			root->iadd(s);
		}else if(op == 1){
			root->iraze(s);
		}else if(op == 2){
			fout << root->ifind(s) << "\n";
		}else{
			fout << root->iprefix(s) << "\n";
		}
	}
	return 0;
}