Fetching Unique XML Tags based on Values

Listing down the unique values of a tag in entire XML

Below is the raw information in the form of an XML

<?xml version="1.0" encoding="UTF-8"?>

<STATES>

<STATE>

<NAME>TELANGANA</NAME>

<REGION>SOUTH</REGION>

<CAPITAL>HYDERABAD</CAPITAL>

</STATE>

<STATE>

<NAME>TAMILNADU</NAME>

<REGION>SOUTH</REGION>

<CAPITAL>CHENNAI</CAPITAL>

</STATE>

<STATE>

<NAME>KARNATAKA</NAME>

<REGION>SOUTH</REGION>

<CAPITAL>BENGALURU</CAPITAL>

</STATE>

<STATE>

<NAME>KERALA</NAME>

<REGION>SOUTH</REGION>

<CAPITAL>TRIVANDRUM</CAPITAL>

</STATE>

<STATE>

<NAME>MAHARASHTRA</NAME>

<REGION>WEST</REGION>

<CAPITAL>MUMBAI</CAPITAL>

</STATE>

<STATE>

<NAME>TELANGANA</NAME>

<REGION>SOUTH</REGION>

<CAPITAL>HYDERABAD</CAPITAL>

</STATE>

<STATE>

<NAME>TAMILNADU</NAME>

<REGION>SOUTH</REGION>

<CAPITAL>CHENNAI</CAPITAL>

</STATE>

</STATES>

I want to get only the unique state names from the above information. (TELANGANA,TAMILNADU,KARNATAKA,KERALA,MAHARASHTRA)

//STATE/NAME[not(. = ../following-sibling::STATE/NAME)]

Credits : 

Padmapriya Iyengar (padmapriya.iyengar@gmail.com)