question: If exactly two parrots are sitting on tree branches, both of them having at least some green on their bodies, but only one with a blue head.
#1 return parrots 
#2 return tree branches 
#3 return #1 sitting on #2 
#4 return body of #3 
#5 return #3 where  #4 has at least some green 
#6 return head of #5 
#7 return #5 where  #6 is blue 
#8 return number of  #5 
#9 return number of  #7 
#10 return if  #8 is equal to  two 
#11 return if  #9 is equal to  one 
#12 return if  both  #10 and #11 are true