exp =
  File.read!("input")
  |> String.split("\n", trim: true)
  |> Enum.map(&String.to_integer/1)

[part_1 | _] = for x <- exp, y <- exp, x + y == 2020, do: x * y
IO.puts(part_1)

[part_2 | _] = for x <- exp, y <- exp, z <- exp, x + y + z == 2020, do: x * y * z
IO.puts(part_2)