#include <iostream>
#include <stdlib.h>
#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=nrfii=0;
        memset(fiu,0,sizeof(fiu));
    }
};
Trie *T=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 != T ) {
        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 s[32];
    while(f.getline(s,32))
    {
        s[strlen(s)]='\n';
        switch(s[0])
        {
        case '0':ins(T,s+2);break;
        case '1':del(T,s+2);break;
        case '2':g<<que(T,s+2)<<endl;break;
        case '3':g<<pre(T,s+2,0)<<endl;break;
        }
    }
    return 0;
}