//#include <bits\stdc++.h>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <cstdlib>
#include <vector>
#include <map>
#include <stack>
#include <queue>
#include <algorithm>
#include <ctime>
#include <set>
#include <cmath>
#define sqr(x) (x)*(x)
#define eps 1e-10
#define lson (p<<1)
#define rson (lson | 1)

using namespace std;
const int N = 1e5+10;
const int M = 1e6+10;
typedef long long llg;
struct Node
{
    int num,snum;
    Node* son[30];
    Node() {for(int i=0;i<30;i++) son[i] = NULL;num=snum=0;}
}*rt,*tmp;
char s[33],p[33];
void Insert(char* s)
{
    tmp = rt;
    tmp->num++;
    for(int i=0;s[i];i++)
    {
        if(tmp->son[s[i]-'a' ] == NULL) tmp->son[s[i]-'a' ] = new Node();
        tmp = tmp->son[s[i]-'a' ];
        tmp->num++;
    }
}
void Del(char* s)
{
    int i;
    tmp = rt;
    for(i=0;s[i];i++)
    {
        if(tmp->son[s[i]-'a' ] == NULL) return;
        tmp = tmp->son[s[i]-'a' ];
    }
    int k = tmp->num;
    tmp = rt;
    for(i=0;s[i];i++)
    {
        //if(tmp->son[s[i]-'a' ] == NULL) return;
        tmp->son[s[i]-'a' ]->num -= k;
        if(tmp->son[s[i]-'a' ]->num == 0) 
        {
            tmp->son[s[i] - 'a'] = NULL;
            return;
        }
        tmp = tmp->son[s[i]-'a' ];
    }
    //tmp->son[s[i]-'a' ] = NULL;
}
bool Find(char* s)
{
    tmp = rt;
    for(int i=0;s[i];i++)
    {
        if(tmp->son[s[i]-'a' ] == NULL) return 0;
        tmp = tmp->son[s[i]-'a' ];
    }
    return 1;
}
int main()
{
    int n;
    while(~scanf("%d",&n) )
    {
        rt = new Node();
        //for(int i=0;i<10;i++) cout<<(rt->son[i] == NULL)<<endl;
        for(int i=0;i<n;i++)
        {
            scanf("%s%s",p,s);
            if(p[0] == 'i' ) Insert(s);
            else if(p[0] == 'd') Del(s);
            else if(p[0] == 's')
            {
                printf("%s\n",Find(s)?"Yes":"No");
            }
        }
    }
    return 0;
}