#include <cstdio>
#include <cstring>

char op[20];
char va[40];

struct {
    int n[27];
    int cnt;
    bool lazy;
}t[3000005];
int mem = 0;

void inser(char *s) {
    int p = 0;
    t[p].cnt++;
    while (char c = *(s++)) {
        if (t[p].n[c-'a'] == 0) {
            t[p].n[c-'a'] = ++mem;
            memset(&t[mem], 0, sizeof(t[0]));
        }
        p = t[p].n[c-'a'];

        if (t[p].lazy) {
            for (int i = 0; i < 26; i++) {
                if (t[p].n[i] != 0) {
                    t[t[p].n[i]].lazy = true;
                    t[t[p].n[i]].cnt = 0;
                }
            }
            t[p].lazy = false;
        }

        t[p].cnt++;
    }
}

void delet(char *s) {
    char *tmp = s;

    int p = 0;
    while (char c = *(s++)) {
        if (t[p].lazy || t[p].cnt == 0) {
            return;
        }
        if (t[p].n[c-'a'] == 0) {
            return;
        }
        p = t[p].n[c-'a'];
    }

    s = tmp;
    int va = t[p].cnt;

    p = 0;
    while (char c = *(s++)) {
        t[p].cnt -= va;
        p = t[p].n[c-'a'];
    }
    t[p].cnt = 0;
    t[p].lazy = true;
}

bool searc(char *s) {
    int p = 0;
    while (char c = *(s++)) {
        if (t[p].lazy || t[p].cnt == 0) {
            return false;
        }
        if (t[p].n[c-'a'] == 0) {
            return false;
        }
        p = t[p].n[c-'a'];
    }
    return t[p].cnt > 0;
}

int main() {
    int n;
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%s %s", op, va);

        if (op[0] == 'i') {
            inser(va);
        } else if (op[0] == 's') {
            if (searc(va)) {
                puts("Yes");
            } else {
                puts("No");
            }
        } else {
            delet(va);
        }
    }
}
/*
10000
i h
i hh
i hhh
i hhhh
i hhhhh
i hhhhhh
d hhhh
s hhhh
s hhhhh
i hhhha
s hhhhh
s hhhha
s hhhhhh
*/