#include <cstdio>
#include <string>

using namespace std;

#define MAXN 26

typedef struct trie {
	int words, prefix;
	trie *child[MAXN];
} trie;

trie *t = new trie;

void read() {
	freopen( "trie.in", "r", stdin );
	freopen( "trie.out", "w", stdout );
}

void add(char *s, trie *tree) {
	if (s[0] < 'a' || s[0] > 'z') {
		tree -> words++;
	} else {
		int index = s[0] - 'a';

		if(!tree -> child[index])
			tree -> child[index] = new trie;

		tree -> prefix++;
		add(s + 1, tree -> child[index]);
	}
}

trie* remove(char *s, trie *tree) {

	if (s[0] < 'a' || s[0] > 'z') {
		tree -> words--;
	} else {
		int index = s[0] - 'a';
		tree -> prefix--;
		if(tree -> child[index] == 0)
			return tree;
		tree -> child[index] = remove(s + 1, tree -> child[index]);
	}

	if (tree -> words == 0 && tree -> prefix == 0)
		return 0;

	return tree;
}

int search_words(char *s, trie *tree) {
	if (s[0] < 'a' || s[0] > 'z') {
		return tree -> words;
	} else {
		int index = s[0] - 'a';
		if (!tree -> child[index])
			return 0;
		else
			return search_words(s + 1, tree -> child[index]);
	}
}

int search_prefixes(char *s, trie *tree, int *rezult) {
	if (s[0] < 'a' || s[0] > 'z') {
		return *rezult;
	} else {
		int index = s[0] - 'a';
		if (!tree -> child[index])
			return 0;
		else{
			(*rezult)++;
			return search_prefixes(s + 1, tree -> child[index], rezult);
		}
	}
}

void solve() {
	char s[26];
	int k, r;
	while(scanf("%d %s", &k, s) == 2) {
		switch(k){
			case 0: add(s, t); break;
			case 1: remove(s, t); break;
			case 2: printf("%d\n", search_words(s, t)); break;
			case 3: r = 0; printf("%d\n", search_prefixes(s, t, &r)); break;
		}
	}
}

int main() {
	read();
	solve();
	return 0;
}