#include <bits/stdc++.h>
using namespace std;

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

string s;

struct trienod{
	int cnt, depth;
	trienod *v[27];
	trienod(int d){
		cnt=0, depth=d;
		for(int i=0;i<=26;++i) v[i]=nullptr;
	}
	void add(){
		cnt++;
		if(depth==s.size()) return;
		char x;
		if(depth+1==s.size()) x=0;
		else x=s[depth+1]-'a'+1;
		if(v[x]==nullptr) v[x]=new trienod(depth+1);
		v[x]->add();
	}
	bool del(){
		cnt--;
		if(depth==s.size()) return !cnt;
		char x;
		if(depth+1==s.size()) x=0;
		else x=s[depth+1]-'a'+1;
		if(v[x]->del()){
			v[x]=nullptr;
			delete v[x];
		}
		return !cnt;
	}
	int srcf(){
		if(depth==s.size()) return cnt;
		char x;
		if(depth+1==s.size()) x=0;
		else x=s[depth+1]-'a'+1;
		if(v[x]==nullptr) return 0;
		return v[x]->srcf();
	}
	int srcp(){
		if(depth+1==s.size()) return depth;
		char x=s[depth+1]-'a'+1;
		if(v[x]==nullptr) return depth;
		return v[x]->srcp();
	}
};

int main(){
	int tip;
	trienod x(-1);
	while(fin>>tip){
		if(tip==EOF) return 0;
		fin>>s;
		if(tip==0) x.add();
		else if(tip==1) x.del();
		else if(tip==2) fout<<x.srcf()<<"\n";
		else fout<<x.srcp()+1<<"\n";
	}
	return 0;
}