#include <bits/stdc++.h>
using namespace std;
const int SIGMA = 26;

struct trie {
	trie *adj[SIGMA];
	int frq, dp;
	trie() {
		frq = 0, dp = 0;
		for(int i=0; i<SIGMA; i++) adj[i] = NULL;
	}
};
trie *start = new trie;

void add(trie *node, char *w) {
	if(*w=='\0') {
		node -> frq ++;
		return;
	}
	if(node -> adj[*w-'a'] == NULL) {
		node -> adj[*w-'a'] = new trie;
		node -> dp ++;
	}
	add(node -> adj[*w-'a'], w+1);
}

bool erase(trie *node, char *w) {
	if(*w=='\0') 
		node -> frq --;
	else if(node -> adj[*w-'a'] != NULL and erase(node -> adj[*w-'a'], w+1)) {
		node -> adj[*w-'a'] = NULL;
		node -> dp --;
	}
	if(node -> frq == 0 and node -> dp == 0 and node!=start) {
		delete node;
		return 1;
	}
	return 0;
}

int query(trie *node, char *w) {
	if(*w=='\0') return node -> frq;
	else if(node -> adj[*w-'a'] != NULL) return query(node -> adj[*w-'a'], w+1);
	return 0;
}

int pref(trie *node, char *w, int lg) {
	if(*w=='\0' or node -> adj[*w-'a']==NULL) return lg;
	return pref(node -> adj[*w-'a'], w+1, lg+1);
}

int main() {
	ifstream f("trie.in");
	ofstream g("trie.out");
	
	int op; char cuv[21]; 
	while(f >> op >> cuv) {
		if(op==0) add(start, cuv);
		else if(op==1) erase(start, cuv);
		else if(op==2) g << query(start, cuv) << "\n";
		else if(op==3) g << pref(start,cuv,0) << "\n";
	}
	return 0;
}