#include <iostream>
#include <fstream>
#include <cstring>
#include <cstdio>
#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=='\0')
    {
        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=='\0')
        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=='\0')
        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=='\0' || nod->fiu[CH]==0)
        return k;
    return pre(nod ->fiu[CH],s+1,k+1);
}
int main()
{
    char line[32];
    while (f.getline(line,32))
        switch(line[0])
        {
            case '0': ins(t,line+2); break;
            case '1': del(t,line+2); break;
            case '2': g<<que(t,line+2)<<'\n'; break;
            case '3': g<<pre(t,line+2,0)<<'\n'; break;
        }

    return 0;
}