Task: Question Generation
Input (English): #1 return Chetnik units attacked the  Partisans 
#2 return Partisans formed the  1st Proletarian Assault Brigade 
#3 return when  was  #1 
#4 return when  was  #2 
#5 return which is the  lowest of #3 ,  #4
Output (English): Which occurred first, Chetnik units attacked the Partisans or Partisans formed the 1st Proletarian Assault Brigade?