#include <stdio.h>
#include <string.h>
struct Node
{
    struct Node *br[26];
    int num;
};
Node *head;
int cnt;

void Tree_insert(char str[])//插入单词
{
    Node *t,*s=head;
    int i,j;
    int len=strlen(str);
    for(i=0;i<len;i++)
    {
        int id=str[i]-'a';
        if(s->br[id]==NULL)
        {
            t=new Node;
            for(j=0;j<26;j++)
            {
                t->br[j]=NULL;
            }
            t->num=0;
            s->br[id]=t;
        }
        s=s->br[id];
        s->num++;
    }
}

int Tree_Find(char str[])
{
    Node *s=head;
    int count,i;
    int len=strlen(str);
    for(i=0;i<len;i++)
    {
        int id=str[i]-'a';
        if(s->br[id]==NULL)
        {
            return 0;
        }
        else
        {
            s=s->br[id];
            count=s->num;
            //if (count == 0) return 0;
        }
    }
    return count;
}

void Tree_Del(char str[])
{
    Node *s=head;
    int i, id;
    int len=strlen(str);
    for(i=0;i<len;i++)
    {
        id=str[i]-'a';
        if(s->br[id]==NULL)
        {
            return;
        }
        else
        {
            s->num -= cnt;
            s=s->br[id];
        }
    }
    s->num = 0;
    for (int i = 0; i < 26; ++i)
        s->br[i] = NULL;
}

int main()
{
    int i;
    head=new Node;
    for(i=0;i<26;i++)
    {
        head->br[i]=NULL;
        head->num=0;
    }
    int n;
    scanf("%d", &n);
    char op[20], s[50];
    while (n--) {
        scanf("%s%s", op, s);
        if (!strcmp(op, "insert"))
            Tree_insert(s);
        else if (!strcmp(op, "delete")) {
            cnt = Tree_Find(s);
            if (cnt <= 0) continue;
            Tree_Del(s);
        }
        else {
            if (Tree_Find(s) > 0)
                puts("Yes");
            else puts("No");
        }
    }
    return 0;
}