#include <iostream>
#include <cstring>

using namespace std;

const int N = 100007;

int h[N], e[N], ne[N], idx;

void insert(int x)  //拉链法，n个头节点，n个链表
{
    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; //先模再加再模

    for (int i = h[k]; i != -1; i = ne[i])
    {
        if (e[i] == x)
            return true;
    }

    return false;
}

int main()
{
    int n;
    scanf("%d", &n);

    memset(h, -1, sizeof h);

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

        if (op[0] == 'I') insert(x);
        else 
        {
            if (find(x)) puts("Yes");
            else puts("No");
        }
    }

    return 0;
}