/* 
 * File:   main.cpp
 * Author: semprathlon
 *
 * Created on May 15, 2016, 10:44 AM
 */

#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <cstring>
#include <string>

using namespace std;

const int maxn = 50;

struct Trie {
    int cnt;
    Trie* child[26];

    Trie() {
        for (int i = 0; i < 26; i++)
            child[i] = NULL;
        cnt = 0;
    }

    void insert(char* s, int len, int p) {
        int ch = s[p] - 'a';
        if (child[ch] == NULL)
            child[ch] = new Trie();
        child[ch]->cnt++;
//        cout<<string(s).substr(0,p+1)<<","<<child[ch]->cnt<<endl;
        if (p < len - 1)
            child[ch]->insert(s, len, p + 1);
    }

    int query(char* s, int len, int p) {
        int ch = s[p] - 'a';
        if (p > len - 1 )
            return -1;
        if (child[ch] == NULL|| child[ch]->cnt < 1)
            return -2;
        
//        cout<<string(s).substr(0,p+1)<<","<<child[ch]->cnt<<endl;
        int tmp=child[ch]->query(s, len, p + 1);
        return tmp>-2?max(tmp,p):-2;
    }

    int del(char* s, int len, int p) {
        int ch = s[p] - 'a';
        if (p > len - 1 || child[ch] == NULL)
            return 0;
        int res = child[ch]->del(s, len, p + 1);
        if (p == len - 1) {
            if (child[ch] != NULL) {
                res = child[ch]->cnt;
            }
        }
        if (child[ch] != NULL) {
            child[ch]->cnt -= res;
            if (child[ch]->cnt < 1) {
                free(child[ch]);
                child[ch] = NULL;
            }
        }
        return res;
    }
} *tr;

char str[maxn], op[maxn];

int main(int argc, char** argv) {
    int n;
    scanf("%d", &n);
    tr = new Trie();
    while (n--) {
        scanf("%s%s", op, str);
        if (op[0] == 'i') {
            tr->insert(str, strlen(str), 0);
        } else if (op[0] == 's') {
            puts(tr->query(str, strlen(str), 0) >= 0 ? "Yes" : "No");
//            cout<<tr->query(str, strlen(str), 0)<<endl;
        } else if (op[0] == 'd') {
            tr->del(str, strlen(str), 0);
        }
    }
    free(tr);
    return 0;
}