UVA - 11220 - Decoding the message

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

public class Main {

    public static void main(String[] args) throws IOException {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);
        StringBuffer sb = new StringBuffer("");
        int cases = Integer.parseInt(br.readLine());
        br.readLine();
        for (int l = 1; l < cases + 1; l++) {
            if(l>1)
                sb.append("\n");
            sb.append("Case #").append(l).append(":\n");
            while(true){
                String m=br.readLine();
                if("".equals(m))
                    break;
                StringTokenizer st=new StringTokenizer(m);
                for(int i=0;st.hasMoreElements();i++){
                    String temp=st.nextToken();
                    while(i>temp.length()-1){
                        try{
                        temp=st.nextToken();
                        }catch(Exception e){
                            break;
                        }
                    }
                    if(!(i>temp.length()-1))
                         sb.append(temp.charAt(i));
                    }
                sb.append("\n");
                }
        }
        System.out.print(sb);
    }

}