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.
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import java.util.Scanner;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

public class a286 {

	static class Task{		
		
		public void solve(InputReader in, PrintWriter out)
		{
			String S=in.next();
			int n=S.length();
		
			int p=0;
			for(int i=0;i<(S.length()+1)/2;i++)
			{
				if(S.charAt(i)!=S.charAt(n-1-i))
				{
					p=1;
					break;
				}
			}
			if(p==0)
			{
				String s="";
				String s1="";
				String al="a";
				if(n%2!=0)
				{
					s=S.substring(0,n/2+1);
				    out.print(s);
				    for(int i=n/2;i>-1;i--)
				    {
				    	out.print(s.charAt(i));
				    }
				    return;
				}
				else
				{
					s=S.substring(0,n/2);
					s1=S.substring(0,n/2);
					s=s.concat(al);
					out.print(s);
					for(int i=n/2-1;i>-1;i--)
					{
					  	out.print(s1.charAt(i));
				    }
				//	out.println(s);
					return;
				}
				
			}
			else
			{
				String s1=S;
				String s2=S;
				for(int i=0;i<(n+1)/2;i++)
				{
					if(s1.charAt(i)!=s1.charAt(n-1-i))
					{
						String temp=Character.toString(s1.charAt(i));
						String t1=s1.substring(0,n-i);
						String t2=s1.substring(n-i,n);
						String t3=(t1.concat(temp)).concat(t2);
						String temp2=Character.toString(s1.charAt(n-1-i));
						String t12=s1.substring(0,i);
						String t22=s1.substring(i,n);
						String t32=(t12.concat(temp2)).concat(t22);
						if(ispalindrome(t3))
						{
							out.println(t3);
							return;
						}
						if(ispalindrome(t32))
						{
							out.println(t32);
							return;
						}
					}
				}
			}
			out.println("NA");
		
		}
	}
       
	
	public static boolean ispalindrome(String s)
	{
		boolean p=true;
		for(int i=0;i<(s.length()+1)/2;i++)
		{
			if(s.charAt(i)!=s.charAt(s.length()-1-i))
			{
				p=false;
				break;
			}
		}
		return p;
	}
	
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Task solver = new Task();
        solver.solve(in,out);
        out.close();
    }
    
    static int[][] sort2D(int arr[][]){
        Arrays.sort(arr,new java.util.Comparator<int[]>(){
        public int compare(int[] a, int[] b) {
            return Integer.compare(a[0], b[0]);
        }});
        return arr;
    }
    
	static int[] di={1,0,-1,0,1,-1,-1,1};
	static int[] dj={0,1,0,-1,1,1,-1,-1};
    
	static class point{
		int x;int y;
		public point(int x,int y){
			this.x=x;
			this.y=y;
		}
	}
    
    static int abs(int x){if(x>=0)return x;else return -x;}
    static int gcd(int a,int b){return b==0?a:gcd(b,a%b);}
    static int min(int x,int y){return x<y?x:y;}
    static int min(int x,int y,int z){return x<y?(x<z?x:z):(y<z?y:z);}
    static int max(int x,int y){return x>y?x:y;}
    static int max(int x,int y,int z){return x>y?(x>z?x:z):(y>z?y:z);}
    
    static long abs(long x){if(x>=0)return x;else return -x;}
    static long gcd(long a,long b){return b==0?a:gcd(b,a%b);}
    static long min(long x,long y){return x<y?x:y;}
    static long min(long x,long y,long z){return x<y?(x<z?x:z):(y<z?y:z);}
    static long max(long x,long y){return x>y?x:y;}
    static long max(long x,long y,long z){return x>y?(x>z?x:z):(y>z?y:z);}
    
   
    static void joutArray(int arr[]){
    	for(int i=0;i<arr.length;i++){
    		System.out.print(arr[i]+" ");
    	}
    }
    
    static void joutArray(int arr[][],int n,int m){
    	for(int i=0;i<n;i++){
    		for(int j=0;j<m;j++)
    		System.out.print(arr[i][j]+" ");
    		System.out.println();
    	}
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }
        
        public String nextLine() {
			String fullLine=null;
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					fullLine=reader.readLine();
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
				return fullLine;
			}
			return fullLine;
		}

        public int nextInt() {
            return Integer.parseInt(next());
        }
        
        public long nextLong() {
        	return Long.parseLong(next());
        }
        
        public double nextDouble() {
        	return Double.parseDouble(next());
        }
        
        public int[] nextIntArray(int n) {
        	int arr[]=new int[n];
        	for(int i=0;i<n;i++)
        		arr[i]=nextInt();
        	return arr;
        }
        
        public char[] nextCharArray(){
        	char arr[]=next().toCharArray();
        	return arr;
        }
        
        public int[][] nextIntArray(int n,int m){
        	int arr[][]=new int[n][m];
        	for(int i=0;i<n;i++)
        		for(int j=0;j<m;j++)
        			arr[i][j]=nextInt();
        	return arr;
        }
     }
    
   }