#include <iostream>
#include <fstream>
#include <cstring>
#define SMAX 25
#define SIGMAR 30
using namespace std;

ifstream fin ("trie.in");
ofstream fout ("trie.out");

char s[SMAX];
struct Nod {
	int cnt;
	Nod *sons[SIGMAR];
	Nod *tata;
	int poz;
	Nod () {
		memset(sons, 0, sizeof(sons));
		cnt = 0;
		tata = 0;
		poz = 26;
	}
};
Nod *root = new Nod();

void insert (Nod *root, char *s) {
	if (!*s) {
		root->cnt += 1;
	}
	else {
		int son = *s - 'a';
		if (!root->sons[son]) {
			root->sons[son] = new Nod();
			root->sons[son]->tata = root;
			root->sons[son]->poz = son;
		}
		insert(root->sons[son], s+1);
	}
}

void del (Nod *root, char *s) {
	if (!*s) {
		root->cnt -= 1;
		if (root -> cnt == 0) {
			root->tata->sons[root->poz] = 0;
			delete root;
		}
	}
	else {
		int son = *s - 'a';
		if (!root->sons[son]) {
			return;
		}
		del(root->sons[son], s+1);
		bool ok = 0;
		for (int i = 0; i < 26; ++i) {
			if (root->sons[i] != 0) {
				ok = 1;
				i = 26;
			}
		}
		if (!ok) {
			root->tata->sons[root->poz] = 0;
			delete root;
		}
	}
}

int dfs (Nod *root, char *s) {
	if (!*s) {
		//cout << root->cnt;
		int ret = root->cnt;
		//cout << ret;
		return ret;
	}
	else {
		int son = *s - 'a';
		if (!root->sons[son]) {
			return 0;
		}
		dfs(root->sons[son], s+1);
	}
	//return 0;
}

void afis (Nod *root, int level) {
	for (int i = 0; i < 26; ++i) {
		if (!root->sons[i]) {
			continue;
		}
		for (int j = 1; j <= level; ++j) {
			cout << " ";
		}
		char c = i + 'a';
		cout << c << " " << root->sons[i]->cnt << endl;
		afis(root->sons[i], level+1);
	}
}

int prefix (Nod *root, char *s) {
	int ret = 0;
	for (int i = 0; i < 26; ++i) {
		if (!root->sons[i]) {
			continue;
		}
		char c = i + 'a';
		if (*s == c) {
			ret = 1 + prefix(root->sons[i], s+1);
		}
	}
	return ret;
}

int main ()
{
	while (fin.getline(s, SMAX)) {
		if (s[0] == '0') {
			insert(root, s+2);
		}
		else
		if (s[0] == '1') {
			del(root, s+2);
		}
		else
		if (s[0] == '2') {
			fout << dfs(root, s+2) << endl;
		}
		else {
			fout << prefix(root, s+2) << endl;
		}
		/*afis(root,0);
		cout << endl;*/
	}
	//afis(root,0);
	
	fin.close();
	fout.close();
	return 0;
}