Dima and Seryozha live in an ordinary dormitory room for two. One day Dima had a date with his girl and he asked Seryozha to leave the room. As a compensation, Seryozha made Dima do his homework.

The teacher gave Seryozha the coordinates of n distinct points on the abscissa axis and asked to consecutively connect them by semi-circus in a certain order: first connect the first point with the second one, then connect the second point with the third one, then the third one with the fourth one and so on to the n-th point. Two points with coordinates (x1, 0) and (x2, 0) should be connected by a semi-circle that passes above the abscissa axis with the diameter that coincides with the segment between points. Seryozha needs to find out if the line on the picture intersects itself. For clarifications, see the picture Seryozha showed to Dima (the left picture has self-intersections, the right picture doesn't have any).

<image>

Seryozha is not a small boy, so the coordinates of the points can be rather large. Help Dima cope with the problem.

Input

The first line contains a single integer n (1 ≤ n ≤ 103). The second line contains n distinct integers x1, x2, ..., xn ( - 106 ≤ xi ≤ 106) — the i-th point has coordinates (xi, 0). The points are not necessarily sorted by their x coordinate.

Output

In the single line print "yes" (without the quotes), if the line has self-intersections. Otherwise, print "no" (without the quotes).

Examples

Input

4
0 10 5 15


Output

yes


Input

4
0 15 5 10


Output

no

Note

The first test from the statement is on the picture to the left, the second test is on the picture to the right.
/*input
1
0
*/
import java.util.*;
import java.lang.*;
import java.io.*;

public class Main
{
	static PrintWriter out;
	static int MOD = 1000000007;
	static FastReader scan;

    /*-------- I/O using short named function ---------*/
	public static String ns(){return scan.next();}
	public static int ni(){return scan.nextInt();}
	public static long nl(){return scan.nextLong();}
	public static double nd(){return scan.nextDouble();}
	public static String nln(){return scan.nextLine();}
	public static void p(Object o){out.print(o);}
	public static void ps(Object o){out.print(o + " ");}
	public static void pn(Object o){out.println(o);}
    /*-------- for output of an array ---------------------*/
     static void iPA(int arr []){
     	 StringBuilder output = new StringBuilder();
	     for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output);
	}
	static void lPA(long arr []){
	     StringBuilder output = new StringBuilder();
	     for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output);
	}
	static void sPA(String arr []){
	     StringBuilder output = new StringBuilder();
	     for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output);
	}
	static void dPA(double arr []){
	     StringBuilder output = new StringBuilder();
	     for(int i=0; i<arr.length; i++)output.append(arr[i] + " ");out.println(output);
	}
    /*-------------- for input in an array ---------------------*/
	static void iIA(int arr[]){
	     for(int i=0; i<arr.length; i++)arr[i] = ni();
	}
	static void lIA(long arr[]){
	     for(int i=0; i<arr.length; i++)arr[i] = nl(); 
	}
	static void sIA(String arr[]){
	     for(int i=0; i<arr.length; i++)arr[i] = ns(); 
	}
	static void dIA(double arr[]){
	     for(int i=0; i<arr.length; i++)arr[i] = nd();
	}
	/*------------ for taking input faster ----------------*/
     static class FastReader
	{
		BufferedReader br;
		StringTokenizer st;

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

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

		int nextInt()
		{
			return Integer.parseInt(next());
		}

		long nextLong()
		{
			return Long.parseLong(next());
		}

		double nextDouble()
		{
			return Double.parseDouble(next());
		}

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

	// Method to check if x is power of 2
    static boolean isPowerOfTwo (int x) { return x!=0 && ((x&(x-1)) == 0);}
    //Method to return lcm of two numbers
    static int gcd(int a, int b){return a==0?b:gcd(b % a, a); }
    // method to return LCM of two numbers
    static int lcm(int a, int b){return (a / gcd(a, b)) * b;}
    //Method to count digit of a number
    static int countDigit(long n){return (int)Math.floor(Math.log10(n) + 1);}

    //Method to find the max in an array
    static int getMax(int arr[]){
    	int max = arr[0];
    	for(int i=0; i<arr.length; i++){
    		max = arr[i]>max?arr[i]:max;
    	}
    	return max;
    }
    //Method to find the min in an array
    static int getMin(int arr[]){
    	int min = arr[0];
    	for(int i=0; i<arr.length; i++){
    		min = min>arr[i]?arr[i]:min;
    	}
    	return min;
    }
    //Method for sorting
	static void ruffle_sort(int[] a) {
		//shandom_ruffle
		Random r=new Random();
		int n=a.length;
		for (int i=0; i<n; i++) {
			int oi=r.nextInt(n);
			int temp=a[i];
			a[i]=a[oi];
			a[oi]=temp;
		}
		
		//sort
		Arrays.sort(a);
	}

	public static void main (String[] args) throws java.lang.Exception
	{
		OutputStream outputStream =System.out;
        out =new PrintWriter(outputStream);
        scan =new FastReader();
		//for fast output sometimes
		StringBuilder sb = new StringBuilder();
		int n = ni();
		int arr[] = new int[n];
		iIA(arr);
		TreeSet<Integer> set = new TreeSet<Integer>();
		set.add(arr[0]);
		if(n>1)
		set.add(arr[1]);
		//set.add(arr[2]);
		set.add(Integer.MAX_VALUE);
		set.add(Integer.MIN_VALUE);
		int first=0, second=0;
		if(n>1){
			first = Math.min(arr[0], arr[1]);
			second = Math.max(arr[0], arr[1]);
		}
		 
		boolean check = false;
		for(int i=3; i<n; i++){
			int min = set.ceiling(arr[i-1]);
			int max = set.ceiling(arr[i]);
			//pn(min + "  " + arr[i]);
			//pn(first + " " + second);
			if(min != Integer.MAX_VALUE){
				if(min<arr[i] && (arr[i-1]>first || arr[i]<second)){
					//pn(1);
					check = true;
					break;
				}
			}
			if(max != Integer.MAX_VALUE){
				if(max<arr[i-1] && (arr[i-1]<second || arr[i]>first)){
					//pn(2);
					check = true;
					break;
				}
			}
			set.add(arr[i-1]);
			first = Math.min(first, arr[i-1]);
			second = Math.max(second, arr[i-1]);

		}
		if(check)
			pn("yes");
		else
			pn("no");
		out.close();
	}
	
}
