#!/usr/bin/env python3

# 99920044 instead of 2020 for bigboy
# p1: 134283487359328
# p2: 1655132197274893972

from sys import argv

i = [int(x) for x in open(argv[1])]

for x in i:
    for y in i:
        if x+y == 2020:
            print(x*y)
            break
    else:
        continue
    break

for x in i:
    for y in i:
        for z in i:
            if x+y+z == 2020:
                print(x*y*z)
                break
        else:
            continue
        break
    else:
        continue
    break