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

using namespace std;

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

struct _nod{
    int nrSons=0, nrEnd=0;
    _nod *SONS[26]= {}; //sau map
};
_nod *root=new _nod;

void add(_nod *nod, string str){
    nod->nrSons++;
    for(auto c : str){
        if(nod->SONS[c-'a']==NULL)
            nod->SONS[c-'a']=new _nod;
        nod=nod->SONS[c-'a'];
        nod->nrSons++;
    }
    nod->nrEnd++;
}
void del(_nod *nod, string str){
    nod->nrSons--;
    for(auto c : str){
        nod=nod->SONS[c-'a'];
        nod->nrSons--;
    }
    nod->nrEnd--;
}
int aparitii(_nod *nod, string str){
    for(auto c : str){
        if(nod->SONS[c-'a']==0)
            return 0;
        nod=nod->SONS[c-'a'];
    }
    return nod->nrEnd;
}
int longest_common_prefix(_nod *nod, string str){
    int lcp=0;
    for(auto c : str){
        if(nod->SONS[c-'a']==0 || nod->SONS[c-'a']->nrSons==0)
            break;
        lcp++;
        nod=nod->SONS[c-'a'];
    }
    return lcp;
}
void queries(){
    int x;
    string s;
    while(in>>x){
        in>>s;
        if(x==0)
            add(root,s);
        else if(x==1)
            del(root,s);
        else if(x==2)
            out<<aparitii(root,s)<<"\n";
        else if(x==3)
            out<<longest_common_prefix(root,s)<<"\n";
    }
}
int main(){
    queries();
    return 0;
}