#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
using namespace std;

const int N = 30;

struct Node
{
    Node* ch[N];
    int sum;
}*root;

int n;
char s[40], tmp[20];

void Insert()
{
    Node* p = root;
    int len = strlen(s);
    for(int i = 0; i < len; i++)
    {
        //printf("%c", s[i]);
        int k = s[i]-'a';
        if(p->ch[k] == NULL)
        {
            Node* q = (Node*)malloc(sizeof(Node));
            for(int j = 0; j < N; j++) q->ch[j] = 0;
            q->sum = 0;
            p->ch[k] = q;
        }
        p->sum++;
        p = p->ch[k];
    }
    p->sum++;
    //printf("\n");
}

void Search()
{
    //printf("##################         %s\n", s);
    int len = strlen(s);
    Node* p = root;
    for(int i = 0; i < len; i++)
    {
        int k = s[i]-'a';
        //printf("%c", s[i]);
        if(p->ch[k] == NULL || p->sum == 0) {printf("No\n"); return;}
        p = p->ch[k];
    }
    //printf("\n");
    if(p->sum != 0) printf("Yes\n");
    //if(p->sum != 0) printf("@@@@@@@@@@@%5d\n", p->sum);
    else printf("No\n");
}

void Del(Node* p)
{
    if(p == NULL || p->sum == 0) return;
    p->sum = 0;

    //printf("%d\n", p->sum);
    for(int i = 0; i < N; i++)
    {
        if(p->ch[i] != NULL)
        {
            //printf("%c", i+'a');
            Del(p->ch[i]);
        }
    }
}

void Delete()
{
    int len = strlen(s);
    Node* p = root;
    for(int i = 0; i < len; i++)
    {
        int k = s[i]-'a';
        if(p->ch[k] == NULL) return;
        p = p->ch[k];
        //printf("%c", k+'a');
    }
    int sum = p->sum;

    Del(p);
    p = root;
    for(int i = 0; i < len; i++)
    {
        p->sum -= sum;
        int k = s[i]-'a';
        //if(p->ch[k] == NULL) return;
        p = p->ch[k];

        //printf("%c", k+'a');
    }
    //p->sum -= sum;
}

void Work()
{
    root = (Node*) malloc(sizeof(Node));
    for(int i = 0; i < N; i++) root->ch[i] = 0;
    root->sum = 0;
    for(int i = 0; i < n; i++)
    {
        scanf("%s%s", tmp, s);
        if(strcmp(tmp, "insert") == 0) Insert();
        else if(strcmp(tmp, "search") == 0) Search();
        else if(strcmp(tmp, "delete") == 0) Delete();
    }
}

int main()
{
    //freopen("test.in", "r", stdin);
    while(~scanf("%d", &n))
    {
        Work();
    }
}