#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <queue>
#include <time.h>
#define maxn 100007
#define grantN 1000007
#define modp 1000000007
#define mmmp 9973
#define eps (5E-1)
#define minf2 (1E-10)
#define lim1 30
#define lim2 300

using namespace std;

typedef long long LL;
const double PI=4*atan(1);
const double PI2=PI*2;
int n,m,tot;
LL gg,jj;

typedef struct sege
{
    int st,cnt;
    int nxt[27];
    //struct sege *nxt[27];
    friend int operator<(struct sege x, struct sege y)
    {
        return x.st<y.st;
    }
}E,*Ptr;

typedef struct mat {
    int m[10][10];
    int n;
    friend struct mat operator*(struct mat x, struct mat y)
    {
        struct mat r;
        r.n=x.n;
        for (int i=0;i<r.n;++i)
        for (int j=0;j<r.n;++j)
        {
            r.m[i][j]=0;
            for (int k=0;k<r.n;++k) r.m[i][j]+=x.m[i][k]*y.m[k][j];
        }
        return r;
    }
}MA;

LL qpow(int x, LL y, int p)
{
    LL res=1,b=x;
    while (y)
    {
        if (y&1) res=res*b%p;
        b=b*b%p;
        y>>=1;
    }
    return res;
}

void extgcd(int a, int b, int &x, int &y)
{
    if (b != 0) {
        extgcd(b, a % b, y, x);
        y -= (a / b) * x;
    }
    else {
        x = 1;
        y = 0;
    }
}

int mod_inv(int a, int p)
{
    int x, y;
    extgcd(a, p, x, y);
    return (p + x % p) % p;
}

int invm(int x, int p)
{
    x%=p;
    if (x==0) return 0;
    else return mod_inv(x,p);
}

int crt(int x, int m1, int y, int m2)
{
    if (y>x) return ((y-x)%m2*invm(m1,m2)%m2*m1%m2+x)%m2;
    else return ((x-y)%m1*invm(m2,m1)%m1*m2%m1+y)%m1;
}

E e[grantN];

char s[40],t[40];

void ins(int en, char * s)
{
    if ((*s)=='\0')
    {
        e[en].st=1;
        ++e[en].cnt;
        return;
    }
    int k=*s-'a';
    if (e[en].nxt[k]==-1)
    {
        e[en].nxt[k]=++tot;
        for (int i=0;i<26;++i) e[tot].nxt[i]=-1;
        e[tot].st=0;
        e[tot].cnt=0;
    }
    ++e[en].cnt;
    ins(e[en].nxt[k],s+1);
}

int del(int en, char * s)
{
    int k=*s-'a';
    if (*(s+1)=='\0')
    {
        int tmp;
        e[en].cnt-=(tmp=e[e[en].nxt[k]].cnt);
        e[en].nxt[k]=-1;
        return tmp;
    }
    int tmp=0;
    if (e[en].nxt[k]!=-1)
    {
        e[en].cnt-=(tmp=del(e[en].nxt[k],s+1));
    }
    return tmp;
}

int mfind(int en, char * s)
{
    if ((*s)=='\0')
    {
        return e[en].cnt;
    }
    int k=*s-'a';
    if (e[en].nxt[k]!=-1)
    {
        return mfind(e[en].nxt[k],s+1);
    }
    else return 0;
}


int main()
{
    int T;
    LL N;
    //scanf("%d",&T);
    //T=1;
    srand(time(0));
    while (scanf("%d",&n)!=EOF)
    //printf("%d\n",strcmp("aaa","aaa"));
    //while (T--)
    //for (int ci=1;ci<=T;++ci)
    {
        for (int i=0;i<26;++i) e[0].nxt[i]=-1;
        tot=0;
        for (int i=0;i<n;++i)
        {
            scanf("%s%s",s,t);
            if (s[0]=='i') ins(0,t);
            if (s[0]=='d') del(0,t);
            if (s[0]=='s') printf("%s\n",mfind(0,t)?"Yes":"No");
        }
    }
    return 0;
}