public class Reverse {
public static void main(String args[]) {
StringBuilder array = new StringBuilder();
array.append("abcderr");
for(int i=0;i<array.length()/2;i++)
{
char temp=array.charAt(i);
array.replace(i, i+1,array.charAt(array.length()-1-i)+"");
array.replace(array.length()-i-1,array.length()-i,temp+"");
}
System.out.print(array);
}}