class   LetterOne  implements  Runnable{

@Override

public void run() {

char letter[]=new char[26];

for(int i=0;i<letter.length;i++){

letter[i]=(char)('a'+i);

System.out.print(letter[i]);

try {

Thread.sleep(1000);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

public class Letter {

}

public class Test {

public static void main(String[] args) {

LetterOne  le=new LetterOne();

Thread  th=new Thread(le);

th.start();

}

}