#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
#include <set>
int arr[2323];
char ss[23];
char ttt[23];
struct Node{
    Node *child[26];
    int cnt;
};
Node* root;
Node* addN(){
    Node* u = new Node;
    for(int i = 0; i < 26; i++){
        u->child[i] = NULL;
    }
    return u;
}
void removeT(Node* u){
    if(u == NULL) return ;
    for(int i = 0; i < 26; i++)
        removeT(u->child[i]);
    delete (u);
    u = NULL;
    return ;
}
void inSert(char *s){
    Node* u = root;
    int len  = strlen(s);
    for(int i = 0; i < len; i++){
        int k = s[i]-'a';
        if(u->child[k] == NULL){
            Node* newnode = addN();
            u->child[k] = newnode;
            u = newnode;
            u->cnt = 1;
        }else{
            u = u->child[k];
            u->cnt++;
        }
    }
}
int findS(char *s){
    Node* u = root;int len = strlen(s);
    for(int i = 0; i <len ; i++){
        int k = s[i]-'a';
        if(u->child[k]!=NULL)
            u = u->child[k];
        else
            return 0;
    }
    return u->cnt;
}
void deleteS(char *s){
    int k = findS(s);
    if(!k) return ;
    int len = strlen(s);
    Node *u = root->child[s[0]-'a'];
    Node *pre = root;
    for(int i = 1; i < len; i++){
        u->cnt -= k;
        if(u->cnt == 0){
            pre->child[s[i-1]-'a'] = NULL;
            removeT(u);
            return ;
        }
        pre = u;
        u = u->child[s[i] - 'a'];
    }pre->child[s[len-1]-'a'] = NULL;
    removeT(u);
}
char s[55], Cmmd[52];
int main(){
    int n;
    while(scanf("%d", &n) != EOF){
        root = addN();root->cnt = 0;
        for(int i=0; i < n; i++){
            scanf("%s %s", Cmmd, s);
            if(Cmmd[0] == 'i')
                inSert(s);
            else if(Cmmd[0] == 's'){
                if(findS(s) > 0) printf("Yes\n");
                else
                    printf("No\n");
            }
            else{
                deleteS(s);
            }
        }
        removeT(root);
    }
    return 0;
}