#include<stdio.h>
#include<vector>
#include<cstring>
using namespace std;
#define lgmax 23
struct nod{ long v[27], nr, nctr;
    void init()
    {
        for (char ii='a';ii!='z';ii++)
            v[ii-'a']=0;
    }
};
vector <nod> tr;
nod ng;
long i, n, op, ls, y;
char s[lgmax];

void adauga(long x, long poz)
{
    if (poz==ls)
        tr[x].nr++;
    else
    {
        y=tr[x].v[s[poz]-'a'];
        if (y==0)
        {   y=tr.size();  tr.push_back(ng);  }
        tr[x].v[s[poz]-'a']=y;
        adauga(y,poz+1);
    }
    tr[x].nctr++;
}

void sterge(long x, long poz)
{
    if (poz==ls)
        tr[x].nr--;
    else
    {
        y=tr[x].v[s[poz]-'a'];
        sterge(y,poz+1);
    }
    tr[x].nctr--;
}

void query1(long x, long poz)
{
    if (poz==ls)
        printf("%ld\n",tr[x].nr);
    else
    {
        y=tr[x].v[s[poz]-'a'];
        if (y==0)
            printf("0\n");
        else
            query1(y,poz+1);
    }
}

void query2(long x, long poz)
{
    if (poz==ls)
        printf("%ld\n",poz-1);
    else
    {
        y=tr[x].v[s[poz]-'a'];
        if ((y==0)||(tr[y].nctr==0))
            printf("%ld\n",poz);
        else
            query2(y,poz+1);
    }
}

int main()
{
    freopen("trie.in","r",stdin);
    freopen("trie.out","w",stdout);
    tr.push_back(ng);   tr.push_back(ng);
    tr[0].nctr=tr[1].nctr=1;
    while (1)
    {
        op=-1;  scanf("%ld %s",&op,&s);
        ls=strlen(s);
        if (op==-1)
            break;
        if (op==0)
            adauga(1,0);
        if (op==1)
            sterge(1,0);
        if (op==2)
            query1(1,0);
        if (op==3)
            query2(1,0);
    }
    return 0;
}