#include <iostream>



class Queque
{

public:

	void pushBack( int  b ) {

		if (size == 0) {
			initArray(256);
		}

		if (count == size) {
			extendMem();
			head = 0;
			tail = size / 2;
		}
			array[ tail % size ] = b;
			tail++;
			count++;

	}

	int popFront() {
		if (count == 0) {
			return -1;
		}
		head++;
		count--;
		return array[head - 1];
	}
	void clear() {
		delete[] array;
	}

private :
	int count = 0;
	int size = 0;
	int head = 0;
	int tail = 0;
	int *array;


	void extendMem()
	{
		int i = 0;

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

		}

		delete[] array;
		array = array1;

	}

	void initArray(int size) {
		array = new int[size];
		this->size = size;
	}

};


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

	std::cin >> n;


	for (int i = 1; i <= n; i++) {
		std::cin >> a >> b;
		if (a == 2) {
			if (b == Myclass.popFront() && (flag)) {
				flag = true;
			}
			else {
				flag = false;
			}
		}
		if (a == 3) {
			Myclass.pushBack(b);
		}
	}

	if (flag) {
		std::cout << "YES";
	}
	else {
		std::cout << "NO";
	}
	Myclass.clear();
	return 0;
}