99
1
3
2
2
3
1
1
3
3
3
3
3
3
1
1
3
3
3
3
1
1
3
2
1
1
1
1
1
1
1
3
2
2
2
1
3
3
1
1
3
2
1
3
3
1
2
3
3
3
1
2
2
2
3
3
3
3
3
3
2
2
2
2
3
3
3
1
1
3
2
1
1
2
2
2
3
3
2
1
1
2
2
1
3
2
1
1
2
3
3
3
3
2
2
2
2
2
1
3
 1
3
 2
2
1
 5
2
3
3
1
1
 5
2
2
2
2
2
 6
2
2
2
3
1
3
 5
2
3
3
3
3
 1
2
 100
2
2
1
3
1
3
3
1
1
3
1
1
3
2
1
3
1
1
3
3
2
2
3
1
1
2
3
2
2
3
1
1
2
3
2
1
2
2
3
3
1
1
3
1
2
1
3
1
1
3
2
2
2
1
1
1
3
1
3
2
1
2
2
2
3
3
2
1
1
3
3
2
1
2
1
1
3
1
2
3
2
3
3
3
2
2
1
3
1
2
3
1
2
3
3
1
2
1
3
1
 4
1
2
2
1
 3
3
3
1
 8
1
1
1
1
1
1
1
1
 5
1
1
1
1
3
 3
2
2
3
 3
2
2
2
 2
2
2
 4
2
3
3
3
 2
3
2
 100
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
 7
2
2
2
2
2
2
2
 3
2
1
1
 10
2
3
3
3
3
2
2
2
3
2
 3
3
1
3
 2
3
1
 3
1
2
3
 42
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
 2
1
3
 100
2
3
1
2
3
3
3
1
1
1
1
3
3
3
3
1
2
3
3
3
3
3
3
3
1
2
2
2
3
1
1
3
3
3
3
3
3
3
3
1
2
3
3
3
1
1
1
1
3
3
3
3
1
2
3
1
2
2
2
3
3
2
1
3
3
1
2
3
1
1
1
2
2
2
3
1
1
1
1
1
1
3
2
2
2
2
2
2
3
1
2
2
2
2
2
3
3
2
1
1
 3
3
2
2
 3
3
2
3
 2
3
3
 3
2
2
1
 5
1
1
2
2
3
 3
1
3
1
 3
1
1
3

YES
 NO
 NO
 NO
 YES
 NO
 YES
 YES
 NO
 NO
 NO
 YES
 NO
 NO
 YES
 YES
 YES
 NO
 YES
 YES
 NO
 NO
 NO
 NO
 NO
 YES
 YES
 YES
 NO
 NO
 NO
 YES
 NO
 NO
 NO

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.StringTokenizer;

public class Main {
	static String test;

	static class FR {
		BufferedReader br;
		StringTokenizer st;

		public FR() {
			br = new BufferedReader(new InputStreamReader(System.in));
		}

		String st() {
			while (st == null || !st.hasMoreElements()) {
				try {
					st = new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return st.nextToken();
		}

		int in() {
			return Integer.parseInt(st());
		}

		double db() {
			return Double.parseDouble(st());
		}

		long ln() {
			return Long.parseLong(st());
		}

		int[] _arr(int n) {
			int[] arr = new int[n];
			for (int i = 0; i < n; arr[i++] = in())
				;
			return arr;
		}

		public static boolean isWhitespace(int c) {
			return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		}

		String sl() {
			String ss = "";
			try {
				ss = br.readLine();
			} catch (IOException e) {
				e.printStackTrace();
			}
			return ss;
		}

		BigDecimal bi() {
			return new BigDecimal(st());
		}

	}

	public static void main(String[] args) {
		FR s = new FR();
		int n = s.in();
		int a = 0, b = 0, c = 0;
		boolean aa = true, bb = true, cc = false, flag = true;
		for (int i = 0; i < n; i++) {
			int x = s.in();
			if (x == 1) {
				if (aa && bb) {
					cc = true;
					bb = false;
				} else if (aa && cc) {
					cc = false;
					bb = true;
				} else {
					flag = false;
					break;
				}

			} else if (x == 2) {
				if (bb && aa) {
					cc = true;
					aa = false;
				} else if (bb && cc) {
					cc = false;
					aa = true;
				} else {
					flag = false;
				}
			} else if (x == 3) {
				if (cc && aa) {
					bb = true;
					aa = false;
				} else if (bb && cc) {
					bb = false;
					aa = true;
				} else {
					flag = false;
					break;
				}
				

			}
		}
		System.out.println(flag==true?"Yes":"No");
	}
}
