Something happened in Uzhlyandia again... There are riots on the streets... Famous Uzhlyandian superheroes Shean the Sheep and Stas the Giraffe were called in order to save the situation. Upon the arriving, they found that citizens are worried about maximum values of the Main Uzhlyandian Function f, which is defined as follows:

<image>

In the above formula, 1 ≤ l < r ≤ n must hold, where n is the size of the Main Uzhlyandian Array a, and |x| means absolute value of x. But the heroes skipped their math lessons in school, so they asked you for help. Help them calculate the maximum value of f among all possible values of l and r for the given array a.

Input

The first line contains single integer n (2 ≤ n ≤ 105) — the size of the array a.

The second line contains n integers a1, a2, ..., an (-109 ≤ ai ≤ 109) — the array elements.

Output

Print the only integer — the maximum value of f.

Examples

Input

5
1 4 2 3 1


Output

3

Input

4
1 5 4 7


Output

6

Note

In the first sample case, the optimal value of f is reached on intervals [1, 2] and [2, 5].

In the second case maximal value of f is reachable only on the whole array.
import java.io.*;
import java.math.BigInteger;
import java.util.*;

public class main
{
	private static InputStream stream;
	private static byte[] buf = new byte[1024];
	private static int curChar;
	private static int numChars;
	private static SpaceCharFilter filter;
	private static PrintWriter pw;
	private static long mod = 1000000000 + 7;
	private static void soln()
	{
		/*long b1= nextLong();
		long q=nextLong();
		long l =nextLong();
		int m =nextInt();
		HashSet<Long> set = new HashSet<>();
		for(int i=0;i<m;i++)
			set.add(nextLong());
		//int[] arr = nextIntArray(m);
		long b=Math.abs(b1);
		if(q==1) {
			if(set.contains(b1) || b>l)
				pw.println(0);
			else
				pw.println("inf");
		}
		else if(q==-1) {
			if(b<=l) {
				if(!set.contains(b1) || !set.contains(-b1))
					pw.println("inf");
				else
					pw.println(0);
			}else
				pw.println(0);
		} else if(b1==0) {
			if(set.contains(0))
				pw.println(0);
			else
				pw.println("inf");
		}else if(q==0) {
			if(b<=l) {
				if(set.contains(0))
					if(set.contains(b1))
						pw.println(0);
					else
						pw.println(1);
				else
					pw.println("inf");
			}
			else
				pw.println("0");
		}
		else {
			int cnt=0;
			while(Math.abs(b1)<=l) {
				if(!set.contains(b1))
					cnt++;
				b1*=q;
			}
			pw.println(cnt);
		}*/
		int n = nextInt();
		int[] arr = nextIntArray(n);
		long[] diff = new long[n-1];
		for(int i=0;i<n-1;i++)
			diff[i]=Math.abs(arr[i]-arr[i+1]);
		TreeSet<Long> set = new TreeSet<>();
		set.add(0L);
		long totdiff=0;
		long ans = 0;
		for(int i=0;i<n-1;i++) {
			long totdiff1 = 0;
			if(i%2==0) {
				totdiff+=diff[i];
				totdiff1 = totdiff - set.first();
			}
			else {
				totdiff-=diff[i];
				totdiff1 = set.last() - totdiff;
			}
			//totdiff = Math.max(totdiff - set.first(), set.last() - totdiff);
			ans = Math.max(totdiff1, ans);
			set.add(totdiff);
		}
		pw.println(ans);
	}
	public static class Segment {
		private int[] tree;
		private boolean[] lazy;
		private int size;
		private int n;
		private class node{
			private int a;
			private int b;
			private int c;
			public node(int x,int y,int z){
				a=x;
				b=y;
				c=z;
			}
		}
		public Segment(int n){
			//this.base=arr;
			int x = (int) (Math.ceil(Math.log(n) / Math.log(2)));
	        size = 2 * (int) Math.pow(2, x) - 1;
			tree=new int[size];
			lazy=new boolean[size];
			this.n=n;
			build(0,0,n-1);
		}
		public void build(int id,int l,int r) {
			if(l==r) {
				return;
			}
			int mid=(l+r)/2;
			build(2*id+1,l,mid);
			build(2*id+2,mid+1,r);
			tree[id]=tree[2*id+1]+tree[2*id+2];
		}
		public int query(int l,int r){
			return queryUtil(l,r,0,0,n-1);
		}
		private int queryUtil(int x,int y,int id,int l,int r){
			if(l>y || x>r) 
				return 0;
			if(x <= l && r<=y) {
				//if(!lazy[id])
					return tree[id];
				//else
				//	return tree[id][0];
			}
			int mid=l+(r-l)/2;
			shift(id);
			return queryUtil(x,y,2*id+1,l,mid)+queryUtil(x,y,2*id+2,mid+1,r);
		}
		public void update(int x,int y,int colour,int id,int l,int r){
			//System.out.println(l+" "+r+" "+x);
			if(x>r || y<l)
				return;
			if(x <= l && r<=y) {
				
				return;
			}
			int mid=l+(r-l)/2;
			shift(id);
			update(x,y,colour,2*id+1,l,mid);
			update(x,y,colour,2*id+2,mid+1,r);
			tree[id]=tree[2*id+1]+tree[2*id+2];
		}
		public void shift(int id) {
			
		}
	}

	public static void fft(double[] a, double[] b, boolean invert) {
		int count = a.length;
		for (int i = 1, j = 0; i < count; i++) {
			int bit = count >> 1;
			for (; j >= bit; bit >>= 1) j -= bit;
			j += bit;
			if (i < j) {
				double temp = a[i];
				a[i] = a[j];
				a[j] = temp;
				temp = b[i];
				b[i] = b[j];
				b[j] = temp;
			}
		}
		for (int len = 2; len <= count; len <<= 1) {
			int halfLen = len >> 1;
			double angle = 2 * Math.PI / len;
			if (invert) angle = -angle;
			double wLenA = Math.cos(angle), wLenB = Math.sin(angle);
			for (int i = 0; i < count; i += len) {
				double wA = 1, wB = 0;
				for (int j = 0; j < halfLen; j++) {
					double uA = a[i + j], uB = b[i + j];
					double vA = a[i + j + halfLen] * wA - b[i + j + halfLen] * wB;
					double vB = a[i + j + halfLen] * wB + b[i + j + halfLen] * wA;
					a[i + j] = uA + vA;
					b[i + j] = uB + vB;
					a[i + j + halfLen] = uA - vA;
					b[i + j + halfLen] = uB - vB;
					double nextWA = wA * wLenA - wB * wLenB;
					wB = wA * wLenB + wB * wLenA;
					wA = nextWA;
				}
			}
		}
		if (invert) {
			for (int i = 0; i < count; i++) {
				a[i] /= count;
				b[i] /= count;
			}
		}
	}
	static void multiply(long[][] a, long[][] b, long m)
	{
		int n = a.length;
		long[][] mul = new long[n][n];
		for (int i = 0; i < n; i++)
		{
			for (int j = 0; j < n; j++)
			{
				mul[i][j] = 0;
				for (int k = 0; k < n; k++)
					mul[i][j] = (mul[i][j] + (a[i][k] * b[k][j]) % m) % m;
			}
		}
		for (int i = 0; i < n; i++)
			for (int j = 0; j < n; j++)
				a[i][j] = mul[i][j];
	}

	private static long pow(long a, long b, long c)
	{
		if (b == 0)
			return 1;
		long p = pow(a, b / 2, c);
		p = (p * p) % c;
		return (b % 2 == 0) ? p : (a * p) % c;
	}

	private static long gcd(long n, long l)
	{
		if (l == 0)
			return n;
		return gcd(l, n % l);
	}
	public static void main(String[] args) throws Exception
	{
//		new Thread(null, new Runnable()
//		{
//			@Override
//			public void run()
//			{
//				/*try { 
//					InputReader(new FileInputStream("C:\\Users\\hardik\\Desktop\\B-large-practice.in")); 
//				} catch (FileNotFoundException e) { // TODO Auto-generated catch block
//					e.printStackTrace(); 
//				} */
//				InputReader(System.in);
//				pw = new PrintWriter(System.out);
//				/*try { 
//					pw=new PrintWriter(new FileOutputStream("C:\\Users\\hardik\\Desktop\\out.txt")); 
//				} catch (FileNotFoundException e) { // TODO Auto-generated catch block
//					e.printStackTrace();
//				}*/
//				soln();
//				pw.close();
//			}
//		}, "1", 1 << 26).start();
		
		/*try { 
			InputReader(new FileInputStream("C:\\Users\\hardik\\Desktop\\B-large-practice.in")); 
		} catch (FileNotFoundException e) { // TODO Auto-generated catch block
			e.printStackTrace(); 
		} */
		InputReader(System.in);
		pw = new PrintWriter(System.out);
		/*try { 
			pw=new PrintWriter(new FileOutputStream("C:\\Users\\hardik\\Desktop\\out.txt")); 
		} catch (FileNotFoundException e) { // TODO Auto-generated catch block
			e.printStackTrace();
		}*/
		soln();
		pw.close();
	}

	public static void InputReader(InputStream stream1)
	{
		stream = stream1;
	}

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

	private static boolean isEndOfLine(int c)
	{
		return c == '\n' || c == '\r' || c == -1;
	}

	private static int read()
	{
		if (numChars == -1)
			throw new InputMismatchException();
		if (curChar >= numChars)
		{
			curChar = 0;
			try
			{
				numChars = stream.read(buf);
			} catch (IOException e)
			{
				throw new InputMismatchException();
			}
			if (numChars <= 0)
				return -1;
		}
		return buf[curChar++];
	}

	private static int nextInt()
	{
		int c = read();
		while (isSpaceChar(c))
			c = read();
		int sgn = 1;
		if (c == '-')
		{
			sgn = -1;
			c = read();
		}
		int res = 0;
		do
		{
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}

	private static long nextLong()
	{
		int c = read();
		while (isSpaceChar(c))
			c = read();
		int sgn = 1;
		if (c == '-')
		{
			sgn = -1;
			c = read();
		}
		long res = 0;
		do
		{
			if (c < '0' || c > '9')
				throw new InputMismatchException();
			res *= 10;
			res += c - '0';
			c = read();
		} while (!isSpaceChar(c));
		return res * sgn;
	}

	private static String nextToken()
	{
		int c = read();
		while (isSpaceChar(c))
			c = read();
		StringBuilder res = new StringBuilder();
		do
		{
			res.appendCodePoint(c);
			c = read();
		} while (!isSpaceChar(c));
		return res.toString();
	}

	private static String nextLine()
	{
		int c = read();
		while (isSpaceChar(c))
			c = read();
		StringBuilder res = new StringBuilder();
		do
		{
			res.appendCodePoint(c);
			c = read();
		} while (!isEndOfLine(c));
		return res.toString();
	}

	private static int[] nextIntArray(int n)
	{
		int[] arr = new int[n];
		for (int i = 0; i < n; i++)
		{
			arr[i] = nextInt();
		}
		return arr;
	}

	private static long[] nextLongArray(int n)
	{
		long[] arr = new long[n];
		for (int i = 0; i < n; i++)
		{
			arr[i] = nextLong();
		}
		return arr;
	}

	private static void pArray(int[] arr)
	{
		for (int i = 0; i < arr.length; i++)
		{
			System.out.print(arr[i] + " ");
		}
		System.out.println();
		return;
	}

	private static void pArray(long[] arr)
	{
		for (int i = 0; i < arr.length; i++)
		{
			System.out.print(arr[i] + " ");
		}
		System.out.println();
		return;
	}

	private static boolean isSpaceChar(int c)
	{
		if (filter != null)
			return filter.isSpaceChar(c);
		return isWhitespace(c);
	}

	private static char nextChar()
	{
		int c = read();
		while (isSpaceChar(c))
			c = read();
		char c1 = (char) c;
		while (!isSpaceChar(c))
			c = read();
		return c1;
	}

	private interface SpaceCharFilter
	{
		public boolean isSpaceChar(int ch);
	}
}