include [HTML_REMOVED]

include [HTML_REMOVED]

using namespace std;
const int N = 200003;
const int null = 0x3f3f3f3f;

int h[N]; //开放寻址法

int sfind(int x){ //在其中插入数值
int k = (x % N + N) % N;
while(h[k] != null && h[k] != x){ //找到其中的那一个空位
k++;
if(k == N) k = 0; //倒回去
}
return k;
}

int main(){
int n,a;

scanf("%d",&n);
memset(h,null,sizeof(h));

while(n--){
    char op[2];
    scanf("%s%d",op,&a);
    int k = sfind(a);


    if(op[0] == 'I'){
        h[k] = a;

    }else{
        if(h[k] == a) cout<<"Yes"<<endl;
        else cout<<"No"<<endl;
    }
}

return 0;

}