#include<iostream>
#include<vector>
#include<string>

using namespace std;

int main()
{
	long num;
	int process;
	string temp;
    vector<string>signal;
    bool judge;
	cin>>num;
	for(long i=1;i<=num;i++)
	{
		cin>>process>>temp;
		if(process==1)
		{
			signal.push_back(temp);
		}
		else
		{
			judge=false;
			for(string *p=signal.begin();p<=signal.end();p++)
			{
				if(*(signal.begin()+p)==temp) judge=true;
			}
			if(judge==true) cout<<"YES"<<endl;
			else cout<<"NO"<<endl;
		}
	}
}
/*#include<iostream>
#include<vector>
#include<string>
using namespace std;

int main()
{
	vector<string>signal;
}*/