#include <iostream>
#include <cstring>

using namespace std;

char cmd[10], str[40];

struct Node {
    int cnt;
    Node* son[26];
};
Node* root;

void insert(char* str) {
    int len = strlen(str);
    Node* t = root;
    t->cnt++;
    for (int i = 0; i < len; i++) {
        int j = str[i] - 'a';
        if (t->son[j] == NULL) {
            t->son[j] = new Node();
        }
        t = t->son[j];
        t->cnt++;
    }
}

void remove(char* str) {
    int len = strlen(str);
    Node* t = root;
    int diff = 0;
    for (int i = 0; i < len; i++) {
        int j = str[i] - 'a';
        if (t->son[j] == NULL) {
            return;
        }
        if (i == len - 1) {
            diff = t->son[j]->cnt;
            t->son[j] = NULL;
        } else {
            t = t->son[j];
        }
    }
    t = root;
    t->cnt -= diff;
    for (int i = 0; i < len; i++) {
        int j = str[i] - 'a';
        if (t->son[j] == NULL) {
            return;
        }
        t = t->son[j];
        t->cnt -= diff;
    }
}

bool search(char* str) {
    int len = strlen(str);
    Node* t = root;
    for (int i = 0; i < len; i++) {
        int j = str[i] - 'a';
        if (t->son[j] == NULL) {
            return false;
        }
        t = t->son[j];
    }
    return (t->cnt > 0);
}

int main() {
    root = new Node();
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%s%s", cmd, str);
        if (strcmp(cmd, "insert") == 0) {
            insert(str);
        } else if (strcmp(cmd, "delete") == 0) {
            remove(str);
        } else if (strcmp(cmd, "search") == 0) {
            bool find = search(str);
            if (find) {
                printf("Yes\n");
            } else {
                printf("No\n");
            }
        }
    }
}