#include<bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops,inline")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define fast ios_base::sync_with_stdio(0);f.tie(0);g.tie(0);
#define setinf(x) memset(x,0x3f3f3f3f,sizeof(x));
#define set0(x) memset(x,0,sizeof(x));
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define INF 0x3f3f3f3f
#define vi vector<int>
#define ll long long
#define vll vector<ll>
#define pb push_back
#define fi first
#define se second
#define DD 100001
#define nl '\n'
using namespace std;
const string file="trie";
ifstream f(file+".in");
ofstream g(file+".out");
//#define f cin
//#define g cout
struct trie {
    struct node {
        node *links[26];
        int cnt,ends;
        node() {
            for (int i = 0; i < 26; i++) {
                links[i] = NULL;
            }
            cnt = 0;
            ends=0;
        }
    };
    node *root;
    trie() {
        root = new node();
    }
    void insert(string s) {
        node * nod=root;
        for (int i=0; i<s.size(); ++i) {
            if (!nod->links[s[i]-'a']) {
                nod->links[s[i]-'a'] = new node();
            }
            nod = nod->links[s[i]-'a'];
            nod->cnt++;
        }
        nod->ends++;
    }
    void erase(string s) {
        node *nod=root;
        for (int i=0; i<s.size(); ++i) {
            if (!nod->links[s[i]-'a']) return;
            nod = nod->links[s[i]-'a'];
            nod->cnt--;
        }
        nod->ends--;
    }
    int search(string s) {
        node *nod=root;
        for (int i=0; i<s.size(); ++i) {
            if (!nod->links[s[i]-'a']) return 0;
            nod = nod->links[s[i]-'a'];
        }
        return nod->ends;
    }
    int prefix(string s) {
        node *nod=root;
        int r=0;
        for (int i=0; i<s.size(); ++i) {
            if (!nod->links[s[i]-'a']) break;
            if (nod->links[s[i]-'a']->cnt==0) break;
            nod = nod->links[s[i]-'a'];
            ++r;
        }
        return r;
    }
};
int main(){
    trie t;
    int n;
    string s;
    while (f>>n>>s) {
        if (n==0) t.insert(s);
        else if (n==1) t.erase(s);
        else if (n==2) g<<t.search(s)<<nl;
        else g<<t.prefix(s)<<nl;
    }
    system("pause");
    return 0;
}