#include<stdio.h>
#include<string>
#include<cmath>
#include<cstring>
#include<iostream>
#include<map>
#include<queue>
#include<algorithm>
using namespace std;
#define ll long long
#define mem(a,x) memset(a,x,sizeof(a))


struct node
{
    node* l[26];
    int num;
};

node* newnode()
{
    node* p = new node;
    p->num = 0;
    mem(p->l,0);
    return p;
}

void Insert(char* s,node* root)
{
    node* cur = root;
    int len = strlen(s);
    for(int i = 0; i < len; i++)
    {
        if(cur->l[s[i]-'a'] == 0)
            cur->l[s[i]-'a'] = newnode();
        cur = cur->l[s[i]-'a'];
        cur -> num++;
    }
}

void Delete(char *s,node* root)
{
    node* cur = root;
    int t;
    int len = strlen(s);
    for(int i = 0; i < len; i++)
    {
        if(cur->l[s[i]-'a'] == 0) return;
        cur = cur->l[s[i]-'a'];
        if((cur->num) == 0) return;
    }
    t = cur->num;
    for(int i = 0;i < 26;i++) cur->l[i] = 0;
    cur = root;
    for(int i = 0; i < len; i++)
    {
        cur = cur->l[s[i]-'a'];
        cur->num -= t;
    }
}

bool query(char* s,node* root)
{
    node* cur = root;
    int len = strlen(s);
    for(int i = 0; i < len; i++)
    {
        if(cur->l[s[i]-'a'] == 0) return false;
        cur = cur->l[s[i]-'a'];
        if(cur->num == 0) return false;
    }
    return true;
}

int main()
{
    int n;
    scanf("%d",&n);
    node* root = newnode();
    for(int i = 0; i < n; i++)
    {
        char op[10];
        char s[35];
        scanf("%s%s",op,s);
        if(op[0] == 'i') Insert(s,root);
        if(op[0] == 'd') Delete(s,root);
        if(op[0] == 's')
        {
            if(query(s,root)) printf("Yes\n");
            else printf("No\n");
        }
    }
    return 0;
}