import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int[] D = new int[8];
		for (int i = 1; i <= 7; i++) {
			D[i] = scanner.nextInt();
		}
		System.out.println(new Solver().solve(D));
	}

}

class Solver {

	public String solve(int[] d) {
		if (isZoukaKadomatsu(d)) {
			return "YES";
		}

		ArrayList<Integer> list = new ArrayList<>();
		list.add(0);
		if (dfs(0, d, new boolean[8], list)) {
			return "YES";
		}

		return "NO";
	}

	private boolean dfs(int i, int[] d, boolean[] bs, ArrayList<Integer> list) {
		bs[i] = true;
		if (all(bs))
			return true;

		for (int j = 1; j <= 7; j++) {
			if (bs[j])
				continue;
			boolean[] newbs = Arrays.copyOf(bs, bs.length);
			ArrayList<Integer> newlist = new ArrayList<>(list);
			newlist.add(d[j]);
			int[] is = new int[newlist.size()];
			for (int k = 0; k < newlist.size(); k++) {
				is[k] = newlist.get(k);
			}
			if (isZoukaKadomatsu(is)) {
				if (dfs(j, d, newbs, newlist)) {
					return true;
				}
			}
		}
		return false;
	}

	private boolean all(boolean[] bs) {
		for (boolean b : bs) {
			if (!b)
				return false;
		}
		return true;
	}

	private boolean isZoukaKadomatsu(int[] d) {
		for (int i = 1; i < d.length - 2; i++) {
			if (!isKadomatsu(d[i], d[i + 1], d[i + 2])) {
				return false;
			}
		}
		return true;
	}

	private boolean isKadomatsu(int i, int j, int k) {
		if (i == j || i == k || j == k)
			return false;
		if (i > k)
			return false;

		return (j > i && j > k) || (j < i && j < k);
	}

}