//拉链法构造哈希表
include[HTML_REMOVED]
include[HTML_REMOVED]
using namespace std;
const int N=1e5+3;
int h[N],e[N],ne[N];
int idx;
void insert(int x)
{
int k=(x%N+N)%N;
e[idx]=x;
ne[idx]=h[k];
h[k]=idx++;
}
bool find(int x)
{
int k=(x%N+N)%N;
for(int i=h[k];i!=-1;i=ne[i])
{
if(e[i]==x) return true;
}
return false;
}
int main()
{
memset(h,-1,sizeof h);
int n;
cin>>n;
while(n–)
{
string op;
int x;
cin>>op;
if(op==”I”)
{
cin>>x;
insert(x);
}else{
cin>>x;
if(find(x)) cout<<”Yes”<<endl;
else cout<<”No”<<endl;
}
}
}