13905
The cluster contains a large number of rare , evolved , high-mass stars , including : 6 yellow hypergiants , 4 red supergiants including Westerlund 1 - 26 , one of the largest known stars , 24 Wolf-Rayet stars , a luminous blue variable , many OB supergiants , and an unusual supergiant sgB [ e ] star which has been proposed to be the remnant of a recent stellar merger .
 Westerlund 1 - 26, Wolf-Rayet
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Westerlund 1 - 26, Wolf-Rayet