import math,itertools as i
  def f(k,p):
  	while(len(p)>k):
  		m=()
  		for r in i.combinations(p,2):
  			d=math.sqrt(sum(map(lambda x,y:(x-y)**2,*r)))
  			if d<m:m=d;x,y=r
  		t=p.remove;t(x);t(y);p+=[map(lambda g,h:(g+h)/2,x,y)]
		print p