question: If a bird is standing on the back of a forward-facing water buffalo in each image.
#1 return bird 
#2 return water buffalo 
#3 return #2 that is forward-facing 
#4 return back of #3 
#5 return #1 that is standing on #4 
#6 return images 
#7 return number of  #5 for each  #6 
#8 return #6 where  #7 is at least one 
#9 return number of  #6 
#10 return number of  #8 
#11 return if  #9 is equal to  #10