// #pragma comment(linker, "/STACK:102400000,102400000")
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>

using namespace std;

#define fr first
#define sc second
#define pb(a) push_back(a)
#define Rint(a) scanf("%d", &a)
#define Rll(a) scanf("%I64d", &a)
#define Rs(a) scanf("%s", a)
#define FRead() freopen("in", "r", stdin)
#define FWrite() freopen("out", "p", stdout)
#define Rep(i, len) for(int i = 0; i < (len); i++)
#define For(i, a, len) for(int i = (a); i < (len); i++)
#define Dec(i, a, b) for(int i = (a); i > (b); i--)
#define Cls(a) memset((a), 0, sizeof(a))
#define Full(a) memset((a), 0x7f7f, sizeof(a))

const int maxn = 1000010;
int n;
char str[55];

typedef struct Trie {
    int t[maxn][26];
    int cnt[maxn], d[55];
    int c, k, p, sz;
    Trie() {
        Cls(cnt); Cls(t);
        sz = 0;
    }
    void insert(char* str) {
        p = 0; cnt[0]++;
        while(*str != 0 && t[p][*str-'a']) {
            p = t[p][*str-'a'];
            cnt[p]++;
            str++;
        }
        while(*str != 0) {
            t[p][*str-'a'] = ++sz;
            p = sz;
            cnt[p]++;
            str++;
        }

    }
    void remove(char* str) {
        k = p = 0; d[k] = 0;
        while(*str != 0 && t[p][*str-'a']) {
            p = t[p][*str-'a'];
            d[++k] = p;
            str++;
        }
        if(*str != 0) return;
        c = cnt[d[k]]; cnt[0] -= c; *str--;
        Dec(i, k, 0) {
            cnt[d[i]] -= c;
            if(!cnt[d[i]]) t[d[i-1]][*str-'a'] = 0;
            str--;
        }
    }
    int find(char* str) {
        p = 0;
        while(*str != 0 && t[p][*str-'a']) {
            p = t[p][*str-'a'];
            str++;
        }
        if(*str == 0) return 1;
        return 0;
    }
}Trie;

Trie root;

int main() {
    // FRead();
    char cmd[55];
    while(~Rint(n)) {
        Rep(i, n) {
            Rs(cmd); Rs(str);
            if(cmd[0] == 'i') root.insert(str);
            if(cmd[0] == 's') {
                if(root.find(str) == 0) printf("No\n");
                else printf("Yes\n");
            }
            if(cmd[0] == 'd') root.remove(str);
        }
    }
    return 0;
}