/*
ID: 1292871202
LANG: C++
*/
#pragma comment(linker,"/STACK:102400000,102400000")
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <iomanip>
#include <cmath>
#include <algorithm>
#include <stack>
#include <queue>
#include <map>
#include <fstream>
#include <utility>

using namespace std;

typedef long long ll;

const int INF = 0x3f3f3f3f;
const int MAX = 0x7fffffff;
const ll LINF = 0x3f3f3f3f3f3f3f3fLL;
const ll LMAX = 0x7fffffffffffffffLL;
const double eps = 1e-9;
const double pi=acos(-1.0);

const int maxn = 100000+5;
const int maxm = 100000+5;
const int mod = 1e9+7;

#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1

struct node
{
    int num;
    node* next[26];
    node()
    {
        num=0;
        for(int i=0; i<26; ++i)
            next[i]=NULL;
    }
};
node *root;

void insert(char s[])
{
    int len=strlen(s);
    node *p=root;
    for(int i=0; i<len; ++i)
    {
        if(p->next[s[i]-'a']==NULL)
            p->next[s[i]-'a']=new node();
        p=p->next[s[i]-'a'];
        p->num++;
    }
}
int query(char s[])
{
    int len=strlen(s);
    node *p=root;
    for(int i=0; i<len; ++i)
    {
        if(p->next[s[i]-'a']==NULL)
            return 0;
        p=p->next[s[i]-'a'];
    }
    return p->num;
}

void del(char s[])
{
    int num = query(s);
    if(num==0)  return;
    int len=strlen(s);

    node*p=root;
    for(int i=0; i<len; ++i)
    {
        p=p->next[s[i]-'a'];
        p->num-=num;
    }
    for(int i=0;i<26;++i)
    {
        p->next[i]=NULL;
    }
}
int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    //cin.sync_with_stdio(false);
    //cout.sync_with_stdio(false);
    int n;
    while(scanf("%d",&n)!=EOF)
    {
        char op[10],s[400];
        root=new node();
        for(int i=0; i<n; ++i)
        {
            scanf("%s%s",op,s);
            if(op[0]=='i')
                insert(s);
            else if(op[0]=='d')
                del(s);
            else
            {
                int num=query(s);
                if(num>0)
                    printf("Yes\n");
                else
                    printf("No\n");
            }
        }
    }
    return 0;
}