33133
There are two long-lived alpha-emitters ; Am has a half-life of 7,370 " years and is the most stable isotope , and Am has a half-life of 432.2 " years .
 Am, Am
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Am, Am