#include <iostream>

using  namespace std;

class Queque
{
public:

	Queque();
	~Queque();
	void pushBack(int  b);
	int popFront();

private:

	int count;
	int size;
	int head;
	int tail;
	int *array;

	void extendMem();

};

Queque::Queque(){
	count = 0;
	size = 8;
	head = 0;
	tail = 0;
	array = new int[size];
}

 void Queque::pushBack(int b) {
	 if ( count == size ) {
		 extendMem();
	 }
	 array[ tail % size ] = b;
	 tail++;
	 count++;
}

 int Queque::popFront() {
	 if ( count == 0 ) {
		 return -1;
	 }
	 head++;
	 count--;
	 return array[ (head - 1) % size ];
 }

 void Queque::extendMem() {
	 int i = 0;
	 int *array1 = new int[size * 2];

	 for ( int j = head; j < tail; j++ ) {
		 array1[i] = array[j % size];
		 i++;
	 }
	 size = size * 2;
	 head = 0;
	 tail = size / 2;
	 delete[] array;
	 array = array1;

 }

Queque::~Queque() {
	delete[] array;
}

int main() {
	int a = 0;
	int b = 0;
	int n = 0;
	bool flag = true;
	Queque Myclass;

	cin >> n;

	for ( int i = 0; i < n; i++ ) {
		cin >> a >> b;
		if (a == 2) {
			if ( b != Myclass.popFront() ) {
				flag = false;
			}
		}
		if (a == 3) {
			Myclass.pushBack(b);
		}
	}

	if ( flag ) {
		cout << "YES";
	}
	else {
		cout << "NO";
	}
	return 0;
}