//#pragma comment(linker, "/STACK:102400000,102400000")
#include<cstdio>
#include<cmath>
#include<iostream>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<map>
#include<set>
#include<stack>
#include<queue>
using namespace std;

#define MZ(array) memset(array, 0, sizeof(array))
#define MF1(array) memset(array, -1, sizeof(array))
#define MINF(array) memset(array, 0x3f, sizeof(array))
#define REP(i,n) for(i=0;i<(n);i++)
#define FOR(i,x,n) for(i=(x);i<=(n);i++)
#define FORD(i,x,y) for(i=(x);i>=(y);i--)
#define RD(x) scanf("%d",&x)
#define RD2(x,y) scanf("%d%d",&x,&y)
#define RD3(x,y,z) scanf("%d%d%d",&x,&y,&z)
#define WN(x) printf("%d\n",x);
#define RE  freopen("D.in","r",stdin)
#define WE  freopen("huzhi.txt","w",stdout)
#define MP make_pair
#define PB push_back
#define PF push_front
#define PPF pop_front
#define PPB pop_back
typedef long long LL;
typedef unsigned long long ULL;

const double PI=acos(-1.0);
const double EPS=1e-10;
const int MAXN=111111;
const int MAXM=33;

class Trie{
public:
    Trie* a[26];
    int n;
    Trie(){
        int i;
        REP(i,26)a[i]=NULL;
        n=0;
    }
};

Trie root;

inline void ins(char s[MAXM]) {
    int l=strlen(s);
    int i,j;
    Trie *pre = &root;
    REP(i,l) {
        int c = s[i] - 'a';
        Trie *x = pre->a[c];
        if(x==NULL) {
            pre->a[c] = new Trie();
            x = pre->a[c];
        }
        pre->n++;
        pre=x;
    }
    pre->n++;
}

inline Trie* sch(char s[MAXM]) {
    int l=strlen(s);
    int i;
    Trie *x = &root;
    REP(i,l) {
        int c = s[i]-'a';
        x = x->a[c];
        if(x==NULL || x->n<=0)return NULL;
    }
    return x;
}

inline void delSon(Trie *x){
    int i;
    if(x->n<=0)return;
    REP(i,26)if(x->a[i]!=NULL){
        delSon(x->a[i]);
    }
//    delete(x);
    x->n=0;
}

inline int del(const int &now, const int &l ,Trie *x, char s[MAXM]) {
    char c = s[now]-'a';
    Trie *w = x->a[c];
    if(w==NULL || w->n<=0)return 0;
    if(now==l-1){
        int n = w->n;
//        x->a[c]=NULL;
        delSon(w);
        return n;
    }
    w->n -= del(now+1, l, w, s);
}

int main() {
    int i,n;
    char c[MAXM],s[MAXM];
    RD(n);
    root = Trie();
    REP(i,n) {
        scanf(" %s %s",c,s);
        if(c[0]=='i')ins(s);
        else if(c[0]=='d')del(0,strlen(s),&root,s);
        else {
            if(sch(s)!=NULL) puts("Yes");
            else puts("No");
        }
    }
    return 0;
}