18956
Overall , “ In a fierce and obstinate conflict on the Somme , which lasted five months , the enemy pressed us back to a depth of about six miles on a stretch of nearly twenty-five miles ” Thirteen new divisions were created by reducing the number of men in infantry battalions , and divisions now had an artillery commander .
 Somme
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Somme