#include<cmath>
#include<math.h>
#include<ctype.h>
#include<algorithm>
#include<bitset>
#include<cassert>
#include<cctype>
#include<cerrno>
#include<cfloat>
#include<ciso646>
#include<climits>
#include<clocale>
#include<complex>
#include<csetjmp>
#include<csignal>
#include<cstdarg>
#include<cstddef>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<cwchar>
#include<cwctype>
#include<deque>
#include<exception>
#include<fstream>
#include<functional>
#include<iomanip>
#include<ios>
#include<iosfwd>
#include<iostream>
#include<istream>
#include<iterator>
#include<limits>
#include<list>
#include<locale>
#include<map>
#include<memory>
#include<new>
#include<numeric>
#include<ostream>
#include<queue>
#include<set>
#include<sstream>
#include<stack>
#include<stdexcept>
#include<streambuf>
#include<string>
#include<typeinfo>
#include<utility>
#include<valarray>
#include<vector>
#include<string.h>
#include<stdlib.h>
#include<stdio.h>
#define ll   long long
#define pb   push_back
#define mp   make_pair
#define orz  1000000007
//作者:中国江苏南京丁天行
//from CrAzYUnIoN
//I prefer being hacked than being FST
using namespace std;
int a[1197700][28],n,s=1;
void cty1(string x){
     int t=1;
     for(int i=0;i<x.size();i++){
             int o=x[i]-'a';
             if(a[t][o])t=a[t][o];
             else a[t][27]++,t=a[t][o]=++s;
     }
}
void cty2(string x){
     int t[40]={1};
     for(int i=0;i<x.size();i++){
             int o=x[i]-'a';
             if(!a[t[i]][o]) return;
             t[i+1]=a[t[i]][o];
     }
     for(int i=x.size()-1;i>=0;i--){
             a[t[i]][x[i]-'a']=0,a[t[i]][27]--;
             if(a[t[i]][27]) return;
     }
}
bool cty3(string x){
     int t=1;
     for(int i=0;i<x.size();i++){
             int o=x[i]-'a';
             if(!a[t][o]) return 0;
             t=a[t][o];
     }
     return 1;
}
int main()
{
    ios::sync_with_stdio(0);
    cin>>n;
    for(int i=1;i<=n;i++){
            string s1,s2;
            cin>>s1>>s2;
            char c='z'+1;
            if(s1[0]=='i')s2+=c,cty1(s2);
            else if(s1[0]=='d')cty2(s2);
            else cout<<(cty3(s2)?"Yes":"No")<<endl;
    }
    //system("pause");
    return 0;
}