#include <iostream>
#include <stdio.h>
#include <string>
using namespace std;
typedef unsigned int uint;
uint sz;

struct TrieNode{
	bool fullWord;
	int wordNumber,fullWordNo;
	TrieNode *links[26];
};
TrieNode* createInstance(){
	TrieNode *node = new TrieNode;
	node->fullWord = false;
	node->wordNumber = 0;
	node->fullWordNo = 0;
	for(int i = 0; i < 26; i++)
		node->links[i] = NULL;
	return node;
}
void add(TrieNode * root,const char word[]){
	TrieNode* current = root;
	for(uint i = 0; i < sz; i++){
		if(current->links[word[i] - 'a'] == NULL)	
			current->links[word[i] - 'a'] = createInstance();
		current = current->links[word[i] - 'a'];
		current->wordNumber++;
	
	}
	current->fullWord = true;
	current->fullWordNo++;

}
void deleteNode(TrieNode* root, const char word[],uint index){
	if(index < sz){
		deleteNode(root->links[word[index] - 'a'],word,index + 1);
		if(root->links[word[index] - 'a']->wordNumber > 1){
			root->links[word[index] - 'a']->wordNumber--;
			if(index == sz - 1 && root->links[word[index] - 'a']->fullWord){
				root->links[word[index] - 'a']->fullWordNo--;
			}
			if(root->links[word[index] - 'a']->fullWordNo < 1)
				root->links[word[index] - 'a']->fullWord = false;
			
		}
		else{
			delete root->links[word[index] - 'a'];
			root->links[word[index] - 'a'] = NULL;
		}
	}
}
void prefix(TrieNode* root, const char w[]){
	int mxm = 0;
	for(uint i = 0; i < sz; i++){
		root = root->links[w[i] - 'a'];
		if(root != NULL){
			mxm++;
		}
		else
			break;
	}
	printf("%d\n",mxm);
}
void wordCount(TrieNode* root,const char w[]){
	int mxm = 0;
	for(uint i = 0; i < sz; i++){
		if(root->links[w[i] - 'a'] == NULL)
			break;
		root = root->links[w[i] - 'a'];
	}
	mxm = root->fullWordNo;
	printf("%d\n",mxm);
}
int main(){
	freopen("trie.in","r",stdin);
	freopen("trie.out","w",stdout);
	string str;
	int q;
	TrieNode* root = createInstance();
//	int c = 0,idx = 0;
	while(cin>>q>>str){
	//	idx++;
	//	cout<<idx<< " " <<str<<" ";
		sz = str.size();
		if(q == 0){
			add(root,str.c_str());
		}
		if(q == 1)	
			deleteNode(root,str.c_str(),0);

		if(q == 2){
			wordCount(root,str.c_str());
		}
		if(q == 3){
			prefix(root,str.c_str());

		}
/*		sz = 8;
		string s = "dezvinui";
		cout<<"---Dezvinui = ";
		wordCount(root,s.c_str());
	//	if(c == 107)
	//		cout<<"index = "<<idx<< " "<<str<<" " << q<<'\n';*/
	}
	return 0;
}
/*
TrieNode* createInstance(){
	TrieNode *node = new TrieNode;
	node->fullWord = false;
	node->wordNumber = 0;
	node->fullWordNo = 0;
	for(int i = 0; i < 26; i++)
		node->links[i] = NULL;
	return node;
}
void add(TrieNode* root,const char w[],int sz){
	TrieNode* current = root;
	int offset = 97;
	for(uint i = 0; i < sz; i++){
		if(current->links[w[i] - offset] == NULL)	
			current->links[w[i] - offset] = createInstance();				
		current = current->links[w[i] - offset];
		current->wordNumber++;
	}
	current->fullWordNo ++;
	current->fullWord = true;
}
void print(TrieNode* root, char branch[],int level){
	if(root->fullWord == true){
		for(int i = 0; i < level;i++)
			cout<<branch[i];
		cout<<'\n';
	}
	for(int i = 0; i < 26; i++){
		if(root->links[i] != NULL){
			branch[level] = i + 'a';
			print(root->links[i],branch,level + 1);
		}
	}
}
void findWord(TrieNode *root,const char word[],int sz){

	for(uint i = 0; i < sz; i++){
		if(root->links[word[i] - 'a'] != NULL)
			root = root->links[word[i] - 'a'];
		else{
			printf("0\n");
			return;
		}
	}
	if(root->fullWord)
		printf("%d\n", root->fullWordNo);
	else
		printf("0\n");
}
void longestPrefix(TrieNode *root,const char word[],int sz){
	int maxim = 0;
	for(uint i = 0; i < sz; i++){
		if(root->links[word[i] - 'a'] != NULL){
			root = root->links[word[i] - 'a'];
			maxim++;
		}
		else
			break;
	}
	printf("%d\n", maxim);
}
void deleteWord(TrieNode *root, const char w[],uint index,int sz){
	if(index < sz){
		deleteWord(root->links[w[index] - 'a'],w,index + 1,sz);
	//	if(index < w.size()){
		if(root->links[w[index] - 'a']->fullWord == true && root->links[w[index] - 'a']->fullWordNo > 1)
				root->links[w[index] - 'a']->fullWordNo--;
			if(root->links[w[index] - 'a']->wordNumber > 1)
				root->links[w[index] - 'a']->wordNumber--;
			else{
				free(root->links[w[index] - 'a']);
				root->links[w[index] - 'a'] = NULL;
			}		
//		}	
	}
}
int main(){
	freopen("trie.in","r",stdin);
	freopen("trie.out","w",stdout);
	string str;
	int q;
	TrieNode* root = createInstance();
	int c = 0,idx = 0;
	while(cin>>q>>str){
		idx++;
		if(q == 0){
			add(root,str.c_str(),str.size());
		}
		if(q == 1){
			
			deleteWord(root,str.c_str(),0,str.size());
		//	char branch[20];
		//	print(root,branch,0);
		}
		if(q == 2){
		//	if(str == "abac")
		//		cout<<"A";
		//	char branch[20];
		//	print(root,branch,0);
			if(str == "dezvinui")
				cout<<"brak";
			findWord(root,str.c_str(),str.size());
			c++;
		}
		if(q == 3){
			longestPrefix(root,str.c_str(),str.size());
			c++;
		}
		if(c == 107)
			cout<<"index = "<<idx<< " "<<str<<" " << q<<'\n';
	}
	return 0;
}*/