#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;

#define MAXL 27
#define MAXO 8
#define MAXA 32
#define BASE 'a'

typedef struct _A
{
    struct _A *next[MAXL];
}A;

A *root;

void init()
{
    root = new A();
}

void insertString(char *word)
{
    A *p = root;
    for (int i = 0, index; word[i] != '\0'; ++i) {
        index = word[i] - BASE;
        if (p->next[index] == NULL){
            p->next[index] = new A();
        }
        p = p->next[index];
    }
}

A* findString(char *word)
{
    A *p = root;
    for (int i = 0, index; word[i] != '\0'; ++i) {
        index = word[i] - BASE;
        if (p->next[index] == NULL) {
            return NULL;
        }
        p = p->next[index];
    }
    return p;
}

void deleteLeafs(A *rt)
{
    for (int i = 0; i < MAXL; ++i) {
        if (rt->next[i] != NULL) {
            deleteLeafs(rt->next[i]);
            rt->next[i] = NULL;
        }
    }
    delete rt;
}

void deletePath(A *pre, A *rt, char *word, bool &flag)
{
    if (word[0] == '\0'){
        for (int i = 0; i < MAXL; ++i) {
            if (pre->next[i] == rt){
                delete rt;
                pre->next[i] = NULL;
                break;
            }
        }
        return;
    }
    int index = word[0] - BASE;
    deletePath(rt, rt->next[index], word+1, flag);
    if (!flag){
        int i;
        for (i = 0; i < MAXL; ++i) {
            if (rt->next[i] != NULL) {
                flag = true;
                break;
            }
        }
        if (!flag) {
            for (int i = 0; i < MAXL; ++i) {
                if (pre->next[i] == rt) {
                    pre->next[i] = NULL;
                    break;
                }
            }
            delete rt;
        }
    }
}

void deleteString(char *word)
{
    A *p = findString(word);
    if (p != NULL) {
        for (int i = 0; i < MAXL; ++i){
            if (p->next[i] != NULL){
                deleteLeafs(p->next[i]);
                p->next[i] = NULL;
            }
        }
        bool flag = false;
        deletePath(root, root->next[word[0]-BASE], word+1, flag);
    }
}

void solve(char *op, char *word)
{
    if (strcmp(op, "insert")==0) {
        insertString(word);
    }
    else if (strcmp(op, "delete")==0) {
        deleteString(word);
    }
    else if (strcmp(op, "search")==0) {
        if (findString(word) != NULL) {
            puts("Yes");
        }
        else {
            puts("No");
        }
    }
}

int main()
{
    int n;
    char op[MAXO], word[MAXA];
    scanf ("%d", &n);
    init();
    while (n--) {
        scanf (" %s%s", op, word);
        solve(op, word);
    }
    return 0;
}