#include <iostream>
#include <fstream>
#include <cstring>
#define CH (*s-'a')
using namespace std;
ifstream f("trie.in");
ofstream g("trie.out");
struct Trie
{
    int cnt,nrfii;
    Trie *fiu[26];
    Trie(){
        cnt=0;nrfii=0;
        memset(fiu,0,sizeof(fiu));
    }

};
Trie *r= new Trie;
void ins(Trie *nod,char *s)
{
    if(*s=='\n')
    {
        nod->cnt++;return;
    }
    if(nod->fiu[CH]==0)
    {
        nod->fiu[CH]=new Trie;
        nod->nrfii++;
    }
    ins(nod->fiu[CH],s+1);
}
int del(Trie *nod, char *s)
{
    if(*s=='\n')
    {
        nod->cnt--;
    }
    else if(del(nod->fiu[CH],s+1))
    {
        nod->fiu[CH]=0;
        nod->nrfii--;
    }
     if( nod->cnt == 0 && nod->nrfii == 0 && nod != r ) {
        delete nod; return 1;
    }
    return 0;
}
int que( Trie *nod, char *s ) {
    if( *s == '\n' )
        return nod->cnt;

    if( nod->fiu[ CH ] )
        return que( nod->fiu[ CH ], s+1 );
    return 0;
}

int pre( Trie *nod, char *s, int k ) {
    if( *s == '\n' || nod->fiu[ CH ] == 0 )
        return k;
    return pre( nod->fiu[ CH ], s+1, k+1 );
}
int main()
{
    char ceva[32];
    while(f.getline(ceva,32))
    {
        ceva[strlen(ceva)]='\n';
        switch(ceva[0])
         {case '0': ins( r, ceva+2 ); break;
            case '1': del( r, ceva+2 ); break;
            case '2': g<<que( r, ceva+2 )<<'\n';  break;
            case '3': g<<pre( r, ceva+2, 0 )<<'\n'; break;
         }
    }
    return 0;
}