#!/a/a/a aN
N
# AaAa.a:N
#	Aa a AaAa a, a a a a a a aN
N
a AaAa:N
	# a_a: a a a a a a a aN
	a_a = 0N
N
	# a a a a a a a a a a a a a, a, a aN
	a = 0N
N
	a __a__(a, a, a):N
		a.a = aN
		a.a = aN
		a.a = 0N
		AaAa.a += 0N
		a.a = AaAa.aN
N
	a aAa(a, a, a):N
		N
		# Aa a a a a a a aN
		aA = (a.a * a.a + a)/(0.0*(a.a+0))N
		aA = (a.a * a.a + a)/(0.0*(a.a+0))N
N
		a.a = aAN
		a.a = aAN
N
		a.a=a(a.a+0, AaAa.a_a)