#include <cstring>
#include <iostream>

using namespace std;
const int maxn = 100003;
unsigned long long e[maxn], ne[maxn], h[maxn], index;
void insert(int x)
{
	int k = (x % maxn + maxn) % maxn;
	e[index] = x;
	ne[index] = h[k];
	h[k] = index;
	index++;
 }
bool find(int x)
{
	int k = (x % maxn + maxn) % maxn;
	for (int i = h[k]; i != -1; i = ne[i])
	{
		if (e[i] == x)
			return true;
	}
	return false;
}
int main()
{
	cin.tie(0);

	memset(h, -1, sizeof(h));
	int n;
	cin >> n;
	while (n--)
	{
		char op[2];
		int x;
		cin >> op >> x;
		if (op[0] == 'I') insert(x);
		else
		{

			if (find(x)) cout << "Yes" << endl;
			else cout << "No" << endl;
		}
	}
 }