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:

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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.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.InputMismatchException;
import java.util.StringTokenizer;

public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(in, out);
        out.close();
    }
}

class Task {

//    List<List<Integer>> g = new ArrayList<>();
    //    static int MAX = 1000;
//    boolean[] used;

    public void solve(Scanner in, PrintWriter out) {
        int n = in.nextInt();
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = in.nextInt();
        }

        int[] b = new int[n - 1];
        for (int i = 0; i < n - 1; i++) {
            b[i] = Math.abs(a[i + 1] - a[i]);
            if (i % 2 == 0) {
                b[i] = -b[i];
            }
        }

        long max = 0;
        long last = 0;
        for (int i = 0; i < n - 1; i++) {
            if (b[i] > 0) {
                last += b[i];
                if (last > max) {
                    max = last;
                }
            } else {
                if (last + b[i] < 0) {
                    last = 0;
                } else {
                    last += b[i];
                }
            }
        }

        for (int i = 0; i < n - 1; i++) {
            b[i] = -b[i];
        }
        long r = max;
        max = 0;
        last = 0;
        for (int i = 0; i < n - 1; i++) {
            if (b[i] > 0) {
                last += b[i];
                if (last > max) {
                    max = last;
                }
            } else {
                if (last + b[i] < 0) {
                    last = 0;
                } else {
                    last += b[i];
                }
            }
        }
        r = Math.max(r, max);
        System.out.println(r);
    }
}


class Utils {

    public static int binarySearch(int[] a, int key) {
        int s = 0;
        int f = a.length;

        while (f > s) {
            int mid = (s + f) / 2;
            if (a[mid] > key) {
                f = mid - 1;
            } else if (a[mid] <= key) {
                s = mid + 1;
            }
        }
        return -1;
    }
}

class Pair<T, U> {
    public T a;
    public U b;

    public Pair(T a, U b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public boolean equals(Object obj) {
        Pair<T, U> p = (Pair<T, U>) obj;
        return p.a.equals(a) || p.a.equals(b);
    }

    @Override
    public int hashCode() {
        return 42;
    }
}


class Vect {
    public int a;
    public int b;

    public Vect(int a, int b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Vect vect = (Vect) o;

        if (a != vect.a) return false;
        return b == vect.b;

    }

    @Override
    public int hashCode() {
        int result = a;
        result = 31 * result + b;
        return result;
    }
}

class Triple<T, U, P> {
    public T a;
    public U b;
    public P c;

    public Triple(T a, U b, P c) {
        this.a = a;
        this.b = b;
        this.c = c;
    }
}


class Scanner {
    BufferedReader in;
    StringTokenizer tok;

    public Scanner(InputStream in) {
        this.in = new BufferedReader(new InputStreamReader(in));
        tok = new StringTokenizer("");
    }

    private String tryReadNextLine() {
        try {
            return in.readLine();
        } catch (Exception e) {
            throw new InputMismatchException();
        }
    }

    public String nextToken() {
        while (!tok.hasMoreTokens()) {
            tok = new StringTokenizer(next());
        }
        return tok.nextToken();
    }

    public String next() {
        String newLine = tryReadNextLine();
        if (newLine == null)
            throw new InputMismatchException();
        return newLine;
    }

    public int nextInt() {
        return Integer.parseInt(nextToken());
    }

    public long nextLong() {
        return Long.parseLong(nextToken());
    }
}