def part1(numbers):
	for i in range(len(numbers)):
		a = numbers[i]
		b = 2020 - a
		if b in numbers[i:]:
			print(a * b)


def part2(numbers):
	for i in range(len(numbers)):
		for j in range(i, len(numbers)):
			a = numbers[i]
			b = numbers[j]
			c = 2020 - a - b
			if c in numbers[j:]:
				print(a * b * c)


with open('input.txt') as fh:
	numbers = [int(l.strip()) for l in fh.readlines()]

part1(numbers)
part2(numbers)