#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define INF numeric_limits<int>::max()
#define int64 long long
#define lsb(x) (-x)&(x)
using namespace std;
ifstream in("trie.in");
ofstream out("trie.out");
struct trie{
    int pref,cuv;
    trie *next[27];
};
trie *T;
char s[1024];
int n;
#define code(x) (x-'a')
void ins(int pos,trie *T)
{
    if(T->next[ code(s[pos]) ]==NULL)
        T->next[ code(s[pos]) ]=new trie;
    T=T->next[ code(s[pos]) ];
    T->pref++;
    if(pos==n-1)
        T->cuv++;
    else
        ins(pos+1,T);
}
void del(int pos,trie *T)
{
    T=T->next[ code(s[pos]) ];
    T->pref--;
    if(pos==n-1)
        T->cuv--;
    else
        del(pos+1,T);
}
int countWords(int pos,trie* T)
{
    if(T->next[ code(s[pos]) ]==NULL)
        return 0;
    T=T->next[ code(s[pos]) ];
    if(pos==n-1)
        return T->cuv;
    else
        return countWords(pos+1,T);
}
int pref;
void maxPref(int pos,trie *T)
{
    if(T->next[ code(s[pos]) ]==NULL)
       return;
    T=T->next[ code(s[pos]) ];
    if(T->pref >= 1)
        pref++;
    else
        return;
    if(pos!=n-1)
        maxPref(pos+1,T);
}
int main()
{
    T=new trie;
    int t;
    while(in>>t>>s)
    {
        n=strlen(s);
        if(t==0)
            ins(0,T);
        else if(t==1)
            del(0,T);
        else if(t==2)
            out<<countWords(0,T)<<'\n';
        else{
            pref=0;
            maxPref(0,T);
            out<<pref<<'\n';
        }
    }
    return 0;
}