#include<iostream>
#include<fstream>
#include<cstring>
using namespace std;
fstream fin("trie.in",ios::in),fout("trie.out",ios::out);
string s;
int maxi;
struct tr
{
    int trm,ct;//cate cuvinte se termina,cate cuvinte trec prin nodul curent
    tr* nxt[26];
    //cout<<"unu\n";
    tr()
    {
        //cout<<"doi\n";
        trm=ct=0;
        memset(nxt,0,sizeof(nxt));
    }
};
tr* t=new tr;
void in_out(tr* pre,tr* n,int p,int op)
{
    //(*n).ct++;
    if(op==0) (n->ct)++;
    if(op==1) (n->ct)--;
    if(op==3 && (n->ct)) maxi=max(maxi,p);
    if(p==s.size())
    {
        if(op==0) (n->trm)++;
        if(op==1) (n->trm)--;
        if(op==2) fout<<(n->trm)<<"\n";
        if(op==3) fout<<maxi<<"\n";
        if(n->trm==0 && n->ct==0 && n!=t)
        {
            pre->nxt[s[p-1]-'a']=NULL;
            delete n;
        }
        return ;
    }
    int nx=s[p]-'a';
    if(n->nxt[nx]==NULL)
        n->nxt[nx]=new tr;
    in_out(n,n->nxt[nx],p+1,op);

    if(n->trm==0 && n->ct==0 && n!=t)
    {
        pre->nxt[s[p-1]-'a']=NULL;
        delete n;
    }
}
int main()
{
    int type;
    while(fin>>type)
    {
        fin>>s;
        maxi=0;
        in_out(t,t,0,type);
    }
}