import sys

inp = open(sys.argv[1], 'r')
out = open(sys.argv[2], 'w')

def getentry():
	line = inp.readline()
	
	while line.startswith('#'):
		line = inp.readline()
	
	for i in range(len(line)):
		if line[i] in [' ', '\t']:
			break
	else:
		raise Exception
	
	return float(line[:i]), float(line[i:])

def writeentry(x, y):
	out.write("%f\t%f\n" % (x, y))

lastx, lasty = getentry()

integral = 0
writeentry(lastx, integral)

while True:
	try:
		x, y = getentry()
	except Exception:
		break
	
	if x < lastx:
		print "Wrong order: %f %f" % (lastx, x)
	
	integral += 0.5 * (x - lastx) * (lasty + y)
	
	writeentry(x, integral)

	lastx = x
	lasty = y