# LaC 2007/11/15

def f(co, a,b,c):
	print "f", a,b,c
	co(a+b+c)

def g(co, a,b):
	print "g", a,b
	co(f, a+b)

def h(co, a,b):
	print "h", a,b
	g(co, a*b, 5)

def call_cc(f, *args):
	l = [True, None]
	def bar(*r):
		l[1:] = r
		if l[0]:
			l[0] = False
			f(bar, *args)
	bar(None, None)
	return l[1:]

def a():
	print "a1"
	print "a2"
	[n, r] = call_cc(h,2,3)
	print "r", r
	print "a3"
	print "a4"
	[r] = call_cc(n,1,4,5)
	print "r", r
	print "a5"

a()