#include<iostream>
#include<cstring>
using namespace std;

const int N = 100003;
int e[N],ne[N],h[N],idx;
void insert(int x) // 要插入的数
{
    int k = (x%N+N) % N; // 要插入的槽
    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;
    for(int i = 0;i < n;i++)
    {
        char op;
        int s;
        cin >> op >> s;
        if(op == 'I')   insert(s);
        if(op == 'Q')
        {
            if(find(s)) cout << "Yes" << endl;
            else cout << "No" <<endl;
        }
    }
    return 0;
}