#!/bin/env python3
import sys
import common

a = common.load_data_from_file(sys.argv[1])
b = common.load_data_from_file(sys.argv[2])

c = set(a.keys())
c.update(b.keys())
keys = list(c)
keys.sort()
for k in keys:
	v_a = a.get(k)
	v_b = b.get(k)
	if v_a is None:
		v = v_b
	elif v_b is None:
		v = v_a
	else:
		v = (v_a + v_b) / 2.0

	print('%s\t%0.3lf' % (k, v))