#include <iostream>
#include <cstring>
#include <cstdio>

using namespace std;

const int N = 200010,null = 0x3f3f3f3f;
int h[N];

int find(int x)
{
    int t = (x % N + N) % N;
    while(h[t] != null && h[t] != x)
    {
        t ++;
        if(t == N) t = 0;
    }
    return t;
}

int main(void)
{
    char op[2];
    int n,x;
    memset(h,0x3f,sizeof h);

    scanf("%d",&n);
    while(n --)
    {
        scanf("%s%d",&op,&x);
        if(*op == ‘I‘)
        {
            h[find(x)] = x;
        }
        else 
        {
            if(h[find(x)] == x) printf("Yes\n");
            else printf("No\n");
        }
    }


    return 0;
}

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

const int N = 100003;
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(void)
{

    memset(h,-1,sizeof h);
    int n,x;
    scanf("%d",&n);
    char op[2];
    while(n --)
    {
        scanf("%s%d",op,&x);
        if(*op == ‘I‘)
        {
            insert(x);
        }
        else 
        {
            if(find(x) == true) printf("Yes\n");
            else printf("No\n");
        }
    }


    return 0;
}