Looping through strings and reversing them until 1 letter is left

Oliver and Lucy play game "Guess: which letter will be the last one?". Lucy names a guessed word and asks Oliver, which letter will be the last one. Rules of the games are the following:
(a) at first, remove every second letter, 
(b) then reverse the string of remaining letters (turn in backward order), 
(c) repeat steps a and b until single letter left. 
For example, when Lucy names word "KARTUPELIS", the wright answer is "I", because KARTUPELIS -> KRUEI -> IEURK ->  IUK -> KUI ->  KU -> IK ->  I. 
Write program that reads data from text file uzd9.in the given words; each word is written in separate line; maximum length of the word is 30 letters; word can include both uppercase, and lowercase Latin alphabet letters; the file contains no more than 100 words. The program must write the last remaind letter for each word after the gameplay in text file uzd9.out; each result in separate line. 
 
Example, Input data Wordsbefore.in KARTUPELIS BUMBA KURMIS SUNS
Output data wordsafter.out   I     A     K      N 

package com.io.java;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class buffered {

	public static void main(String[] args)
	{
		buffered b = new buffered();
		String textFile = "words.txt";
		b.readFile(textFile);
		String newstr = "";
	}
    public void readFile(String strFile) 
	{
		try (BufferedReader buffer = new BufferedReader(new FileReader(strFile)))
			{
				String strBuffer;
				while((strBuffer = buffer.readLine())  != null && strBuffer.length()>1)
				{
					String n = "";
					String newtr = "";
				    int k;
			        char[] c = strBuffer.toCharArray();
				    for( k=0; k<=c.length;k++)
					{
						if(k%2==0)
						{
							newtr+=c[k];
						}
					}
			       newtr = reverse(newtr);
			       c=newtr.toCharArray();
                  if(c.length>0)
                {
                 for(int j = 0; j<=c.length;j++)
                   {
                	   if(j%2==0)
                	   {
                		 n+=c[j];   
                	   }
                   }
                }
                  else
                  {
                	  break;
                  }
                  n = reverse(n);
                   System.out.println(n);
				}
				buffer.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
	}
	public void writeFile(String strFile, String data)
	{
		try(BufferedWriter bwriter = new BufferedWriter(new FileWriter(strFile, true)))
		{
			bwriter.write(data);
		} catch (IOException e) {
			
			e.printStackTrace();
		}
	}
	public String reverse(String s)
	{
		s = new StringBuffer(s).reverse().toString();
		return s;
	}
}