#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <iostream>
#include <vector>
#include <map>
#include <queue>
#include <ctime>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define PB push_back
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define calm (l+r)>>1
const int INF=(int)1e9+7;

char a[10],b[33];
struct node{
    int cnt;
    int next[26];
}tree[3300000];
int vis=0;
void insert(char s[]){
    int rt=0;
    for(int i=0;s[i];i++){
        ++tree[rt].cnt;
        if(!tree[rt].next[s[i]-'a']){
            rt=tree[rt].next[s[i]-'a']=++vis;
        }
        else{
            rt=tree[rt].next[s[i]-'a'];
        }
    }
    ++tree[rt].cnt;
}
bool search(char s[]){
    int rt=0;
    for(int i=0;s[i];i++){
        if(!tree[rt].next[s[i]-'a'])return false;
        rt=tree[rt].next[s[i]-'a'];
        if(!tree[rt].cnt)return false;
    }
    return true;
}
void work(int rt){
    for(int i=0;i<26;i++){
        if(tree[rt].next[i]) {
            work(tree[rt].next[i]);
            tree[rt].next[i]=0;
        }
    }
}
void clear(char s[]){
    int rt=0,i;
    for(i=0;s[i];i++) {
        if (!tree[rt].next[s[i] - 'a'])return;
        if (s[i+1]) {
            rt = tree[rt].next[s[i] - 'a'];
        }
    }
    int t=tree[rt].next[s[i-1]-'a'];
    tree[rt].next[s[i-1]-'a']=0;
    rt=t;
    int sum=tree[rt].cnt;
    work(rt);
    rt=0;
    for(int i=0;s[i];i++){
        tree[rt].cnt-=sum;
        if (!tree[rt].next[s[i] - 'a'])return;
        rt = tree[rt].next[s[i] - 'a'];
    }
    tree[rt].cnt-=sum;
}
int main()
{
    //freopen("/home/xt/code/acm/input.txt","r",stdin);
    int n;scanf("%d",&n);
    for(int i=1;i<=n;i++){
        scanf("%s%s",a,b);
        if(a[0]=='i'){
            insert(b);
        }
        else if(a[0]=='s'){
            if(!search(b)){
                printf("No\n");
            }
            else printf("Yes\n");
        }
        else if(a[0]=='d'){
            clear(b);
        }
    }
    //printf("[Run in %.1fs]\n",(double)clock()/CLOCKS_PER_SEC);
    return 0;
}