// Problem C.cpp
#include <ios>
#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <cstdio>
#include <cwchar>
#include <iosfwd>
#include <limits>
#include <locale>
#include <memory>
#include <string>
#include <vector>
#include <cassert>
#include <ciso646>
#include <climits>
#include <clocale>
#include <complex>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <cwctype>
#include <fstream>
#include <iomanip>
#include <istream>
#include <numeric>
#include <ostream>
#include <sstream>
#include <utility>
#include <iostream>
#include <iterator>
#include <valarray>
#include <algorithm>
#include <exception>
#include <stdexcept>
#include <streambuf>
#include <functional>
#define LL long long
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
#define PI 3.1415926535897932626
#define EXIT exit(0);
#define PAUSE system("pause");
#define DEBUG puts("Here is a BUG");
#define SYNC_CLOSE ios::sync_with_stdio(false);
#define what_is(x) cout << #x << " is " << x << endl;
#define CLEAR(name, init) memset(name, init, sizeof(name));
const double eps = 1e-8;
const int MAXN = (int)1e5 + 5;
using namespace std;
struct Trie {
    int seq;
    bool isStr;
    Trie *next[26];
};
void insert(Trie *root, char const *s) {
    if(root == NULL || *s == '\0') return;
    Trie *p = root;
    while(*s) {
        if(p->next[*s-'a'] == NULL) {
            Trie *temp = (Trie *)malloc(sizeof(Trie));
            memset(temp->next, 0, sizeof(temp->next));
            temp->isStr = false;
            p->next[*s-'a'] = temp;
            p = temp;
            // putchar(*s); cout << temp->seq << ' ';
        }
        else p = p->next[*s-'a'];
        s++;
    }
    p->isStr = true;
    return;
}
bool search(Trie *root, const char *s) {
    Trie *p = root;
    while(NULL != p && *s) {
        p = p->next[*s-'a'];
        // cout << *s << "->" << p << endl;
        s++;
    }
    // if (p) printf("p->seq = %d\n", p->seq);
    return NULL != p;
}
void delet(Trie *root, const char *s) {
    const char *ss = s;
    Trie *p = root, *last = p, *pre = p;
    while(NULL != p && *s) {
        bool flag = false;
        for(int i = 0; i < 26; i++) {
            if (*s - 'a' == i) continue;
            if (NULL != p->next[i]) {
                flag = true;
            }
        }
        if (p->isStr) {
            flag = true;
        }
        if (flag) {
            // DEBUG;
            pre = p;
            last = p->next[*s-'a'];
            ss = s;
            // what_is(*ss);
        }
        p = p->next[*s-'a'];
        s++;
    }
    // if (p) printf("p->seq = %d\n", p->seq);
    if (NULL != p) {
        Trie *tmp = pre;
        // what_is(pre);
        // ss--;
        while(*ss) {
            Trie *net = tmp;
            tmp = tmp->next[*ss-'a'];
            // cout << *(ss) << " " << net->next[*ss-'a'] << endl;
            net->next[*ss-'a'] = NULL;
            ss++;
        }
    }
}
void del(Trie *root) {
    for(int i = 0; i < MAXN; i++) {
        if(root->next[i]) {
            del(root->next[i]);
        }
    }
    free(root);
}
char s[MAXN];
int main(int argc, char const *argv[]) {
#ifndef ONLINE_JUDGE
    freopen("D:\\Documents\\Disk_Synchronous\\Programs\\Acm\\input.txt", "r", stdin);
#endif
    int n;
    while(cin >> n) {
        Trie *root = (Trie *)malloc(sizeof(Trie));
        root->seq = 0; root->isStr = false;
        memset(root->next, 0, sizeof(root->next));
        while(n--) {
            char ord[20];
            scanf("%s%s", ord, s);
            if (ord[0] == 'i') {
                insert(root, s);
            } else if (ord[0] == 's') {
                if (search(root, s)) puts("Yes");
                else puts("No");
            } else {
                delet(root, s);
            }
        }
        // del(root);
    }
    return 0;
}