请写出以下程序运行结：

public class Main {
public static void main(String[] args) {
String s = "hello";
try {
s = s+" world";
s.toUpperCase();
String[] a = s.split("o");
System.out.println(a.length);
} catch (Exception e) {
System.out.print(s);
} finally {
System.out.print(s);
}

3
HELLOWORLD