#include <fstream>
#include <iostream>
#include <string>
#include <cstdio>
#include <cstdlib>
#include <cstring>

#define p pair<int,string>
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");

struct trie {
    int word;
    int prefix;
    trie *edge[26];
   trie () {   word = prefix = 0;
    memset(edge , 0 , sizeof(edge));}
};

trie *T = new trie;
string s;
p num;

p des(string l)
{
    p ret;
    ret.first = (int)toupper(l[0]) - 48;
    l.erase(0,2);
    ret.second = l;
    return ret;
}

void addword(trie *nod, string wd, int r)
{
    if (r == wd.length()) { nod->word++; return;}

    if (nod->edge[wd[r] - 'a' ] == 0 )
    {
         nod ->edge[wd[r] - 'a' ] = new trie;
    nod->prefix++;
   addword(nod->edge[wd[r] - 'a'],wd,r+1);
    }
}

int delword(trie *nod, string wd, int r)
{
    if (r == wd.length() ) nod->word--;
      else
    if (delword(nod->edge[wd[r] - 'a'],wd,r+1))
    {
        nod->edge[wd[r] - 'a'] = 0;
        nod->prefix--;
    }
    if (nod->word == 0 && nod->prefix == 0 && nod != T)
    {        delete nod; return 1;   }
    return 0;
}

int nword(trie *nod,string wd, int r)
{
    if (r == wd.length()) {cout << "prev word : " << wd[r-1] << "\n"; return nod->word; }

    if (nod->edge[wd[r] - 'a'] )
    {
        nword(nod->edge[wd[r] - 'a'],wd,r+1);
    }
    return 0;
}

int npref(trie *nod,string wd , int r , int k)
{
    if ((r == wd.length() )|| (nod->edge[wd[r] - 'a'] == 0))
         { cout << "Last letter : " << wd[r] << "\n"; return k; }

    return npref(nod->edge[wd[r] - 'a'],wd,r+1,k+1);
}

int main()
{

    while (!f.eof())
    {
            getline(f,s);
        num = des(s);
    cout << num.second << " - > " << num.second.length() << "\n";
         switch (num.first)
         {
         case 0 : addword(T,num.second,0); break;
         case 1 : delword(T,num.second,0); break;
         case 2 : cout << (nword(T,num.second,0)) << "\n"; break;
         case 3 : cout << (npref(T,num.second,0,1)) << "\n"; break;
         }

    }

    return 0;
}