Problem: Pari has a friend who loves palindrome numbers. A palindrome number is a number that reads the same forward or backward. For example 12321, 100001 and 1 are palindrome numbers, while 112 and 1021 are not.

Pari is trying to love them too, but only very special and gifted people can understand the beauty behind palindrome numbers. Pari loves integers with even length (i.e. the numbers with even number of digits), so she tries to see a lot of big palindrome numbers with even length (like a 2-digit 11 or 6-digit 122221), so maybe she could see something in them.

Now Pari asks you to write a program that gets a huge integer n from the input and tells what is the n-th even-length positive palindrome number?

Input

The only line of the input contains a single integer n (1 ≤ n ≤ 10100 000).

Output

Print the n-th even-length palindrome number.

Examples

Input

1


Output

11


Input

10


Output

1001

Note

The first 10 even-length palindrome numbers are 11, 22, 33, ... , 88, 99 and 1001.

Solution (in JAVA):

Solution:

import java.io.*;
import java.util.*;

public class CF {

    public static void main(String[] args) throws IOException {
        //FastScanner in = new FastScanner(new FileInputStream(new File("input.txt")));
        //PrintWriter out = new PrintWriter(new File("output.txt"));
        FastScanner in = new FastScanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
        String ch = in.next();
        out.print(ch);
        for (int i = ch.length()-1; i > -1; i--) {
            out.print(ch.charAt(i));
        }
        out.println();
        out.close();
    }

    public static List<int[]> list = new LinkedList<>();

    public static void Permute(int[] input, int startindex) {
        int size = input.length;
        if (size == startindex + 1) {
            int[] tab = new int[size];
            for (int i = 0; i < tab.length; i++) {
                tab[i] = input[i];
            }
            list.add(tab);
        } else {
            for (int i = startindex; i < size; i++) {
                int temp = input[i];
                input[i] = input[startindex];
                input[startindex] = temp;
                Permute(input, startindex + 1);
                int temp2 = input[i];
                input[i] = input[startindex];
                input[startindex] = temp2;
            }
        }
    }

    public static int[] radixSort(int[] f) {
        return radixSort(f, f.length);
    }

    public static int[] radixSort(int[] f, int n) {
        int[] to = new int[n];
        {
            int[] b = new int[65537];
            for (int i = 0; i < n; i++) {
                b[1 + (f[i] & 0xffff)]++;
            }
            for (int i = 1; i <= 65536; i++) {
                b[i] += b[i - 1];
            }
            for (int i = 0; i < n; i++) {
                to[b[f[i] & 0xffff]++] = f[i];
            }
            int[] d = f;
            f = to;
            to = d;
        }
        {
            int[] b = new int[65537];
            for (int i = 0; i < n; i++) {
                b[1 + (f[i] >>> 16)]++;
            }
            for (int i = 1; i <= 65536; i++) {
                b[i] += b[i - 1];
            }
            for (int i = 0; i < n; i++) {
                to[b[f[i] >>> 16]++] = f[i];
            }
            int[] d = f;
            f = to;
            to = d;
        }
        return f;

    }

    private static class FastScanner {

        private final InputStream stream;
        private final byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        public FastScanner(InputStream stream) {
            this.stream = stream;
        }

        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++];
        }

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

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

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

        public int[] nextArrayInt(int n) {
            int tab[] = new int[n];
            for (int i = 0; i < n; i++) {
                tab[i] = nextInt();
            }
            return tab;
        }

        public String[] nextArrayString(int n) {
            String tab[] = new String[n];
            for (int i = 0; i < n; i++) {
                tab[i] = next();
            }
            return tab;
        }

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

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

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

        public String nextLine() {
            int c = read();
            while (isEndline(c)) {
                c = read();
            }
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isEndline(c));
            return res.toString();
        }
    }
}