#include <bits/stdc++.h>
#define car (*c-'a')
using namespace std;
ifstream fin ("trie.in");
ofstream fout ("trie.out");
struct trie
{
    int nr, fii;
    trie *f[27];
    trie()
    {
        nr=fii=0;
        memset(f, 0, sizeof(f));
    }
};
trie *t=new trie;
char c[25];
void add(trie *nod, char *c)
{
    if(*c==0)
       {
           nod->nr++;
           return;
       }
    if(nod->f[car]==0)
    {
        nod->fii++;
        nod->f[car]=new trie;
    }
    add(nod->f[car], c+1);
}
bool del(trie *nod, char *c)
{
    if(*c==0)
        nod->nr--;
    else if(del(nod->f[car], c+1))
    {
        nod->f[car]=0;
        nod->fii--;
    }
    if(nod->nr==0 && nod->fii==0 && nod!=t)
    {
        delete nod;
        return 1;
    }
    return 0;
}
int ap(trie *nod, char *c)
{
    if(*c==0)
        return nod->nr;
    if(nod->f[car]==0)
        return 0;
    return ap(nod->f[car], c+1);
}
int pref(trie *nod, char *c)
{
    if(*c==0 || nod->f[car]==0)
        return 0;
    return 1+pref(nod->f[car], c+1);
}
int main()
{
    while(fin.getline(c, 25))
    {
        if(c[0]=='0')
            add(t, c+2);
        else if(c[0]=='1')
            del(t, c+2);
        else if(c[0]=='2')
            fout << ap(t, c+2) << '\n';
        else fout << pref(t, c+2) << '\n';
    }
    return 0;
}