Here I have two strings. From that, how can I remove common alphabets/characters and store in result(third) String?

```
<%
    String[] firstString = {"google out"};
    String[] secondString = {"stack overflow"};
    String[] result={""};
        for (int i = 0,k=0; i < firstString.length; i++,k++) {
            for (int j = 0; j < secondString.length; j++) {
                if (firstString[i].equalsIgnoreCase(secondString[j])) {
            } else {
                result[k]=result[j]+firstString[i];
                out.println(result[k]);
            }
        }
    }
%>

```

expected result is:  

`g l e o u t s c k v f w`