Problem: Mr. Kitayuta has kindly given you a string s consisting of lowercase English letters. You are asked to insert exactly one lowercase English letter into s to make it a palindrome. A palindrome is a string that reads the same forward and backward. For example, "noon", "testset" and "a" are all palindromes, while "test" and "kitayuta" are not.

You can choose any lowercase English letter, and insert it to any position of s, possibly to the beginning or the end of s. You have to insert a letter even if the given string is already a palindrome.

If it is possible to insert one lowercase English letter into s so that the resulting string will be a palindrome, print the string after the insertion. Otherwise, print "NA" (without quotes, case-sensitive). In case there is more than one palindrome that can be obtained, you are allowed to print any of them.

Input

The only line of the input contains a string s (1 ≤ |s| ≤ 10). Each character in s is a lowercase English letter.

Output

If it is possible to turn s into a palindrome by inserting one lowercase English letter, print the resulting string in a single line. Otherwise, print "NA" (without quotes, case-sensitive). In case there is more than one solution, any of them will be accepted. 

Examples

Input

revive


Output

reviver


Input

ee


Output

eye

Input

kitayuta


Output

NA

Note

For the first sample, insert 'r' to the end of "revive" to obtain a palindrome "reviver".

For the second sample, there is more than one solution. For example, "eve" will also be accepted.

For the third sample, it is not possible to turn "kitayuta" into a palindrome by just inserting one letter.

Solution (in JAVA):

Solution:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Iterator;

public class C505A {
    private static String NA = "NA";

    public static class Palyndrom implements Iterable {
        private char[] string;

        private char markedChar;
        private int markedPosition;

        public static String create(char[] string, char ch, int pos) {
            int left = 0;
            int right = string.length - 1;
            char[] newString = new char[string.length + 2];
            int newLeft = 0;
            int newRight = newString.length - 1;

            while (left <= right) {
                if (newLeft == pos || newRight == pos + 1) {
                    newString[newLeft++] = ch;
                    newString[newRight--] = ch;
                }

                newString[newLeft++] = string[left++];
                newString[newRight--] = string[right--];
            }
            return String.valueOf(newString);
        }

        public static String addChar(char[] string) {
            int left = 0;
            int right = string.length - 1;
            char[] newString = new char[string.length + 1];
            int newLeft = 0;
            int newRight = newString.length - 1;

            while (left <= right) {
                if (right - left == 1) {
                    newString[newLeft++] = string[left++];
                    newString[newRight--] = string[right--];
                    newString[newLeft] = 'y';
                } else if (left == right) {
                    newString[newLeft++] = string[left];
                    newString[newLeft] = string[left++];
                } else {
                    newString[newLeft++] = string[left++];
                    newString[newRight--] = string[right--];
                }
            }

            return String.valueOf(newString);
        }

        public Palyndrom(char[] string) {
            this.string = string;
        }

        public Palyndrom(String string) {
            this.string = string.toCharArray();
        }

        public boolean hasIt() {
            int left = 0;
            int right = string.length - 1;

            while (left <= right) {
                if (string[left++] != string[right--]) {
                    return false;
                }
            }
            return string.length > 0;
        }

        private class PalyndromIterator implements Iterator {
            private int position = 0;

            public PalyndromIterator() {
            }

            @Override
            public boolean hasNext() {
                if (string.length > 1) {
                    return position < string.length;
                }
                return false;
            }

            @Override
            public Object next() {
                char[] p = new char[string.length - 1];
                int i = 0;

                for (int index = 0; index < string.length; index++) {
                    if (position == index) {
                        markedChar = string[position];
                        markedPosition = position;

                        continue;
                    }
                    p[i++] = string[index];
                }
                position++;

                return new Palyndrom(p);
            }

            @Override
            public void remove() {

            }
        }

        @Override
        public Iterator iterator() {
            return new PalyndromIterator();
        }

        public String getString() {
            return String.valueOf(string);
        }

        public char getMarkedChar() {
            return markedChar;
        }

        public int getMarkedPosition() {
            return markedPosition;
        }
    }

    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        Palyndrom palyndrom = new Palyndrom(reader.readLine());
        reader.close();

        if (palyndrom.hasIt()) {
            System.out.println(Palyndrom.addChar(palyndrom.getString().toCharArray()));
        } else {
            Palyndrom miniPalyndrom = null;
            Iterator<Palyndrom> iter = palyndrom.iterator();
            while (iter.hasNext()) {
                Palyndrom p = iter.next();

                if (p.hasIt()) {
                    miniPalyndrom = p;
                    break;
                }
            }

            if (miniPalyndrom == null) {
                System.out.println(NA);
            } else {
                System.out.println(Palyndrom.create(miniPalyndrom.getString().toCharArray(), palyndrom.getMarkedChar(), palyndrom.getMarkedPosition()));
            }
        }
    }
}