Before you leave, the Elves in accounting just need you to fix your expense report (your puzzle input); apparently, something isn’t quite adding up.

Specifically, they need you to find the two entries that sum to 2020 and then multiply those two numbers together.

For example, suppose your expense report contained the following:

1721, 979, 979, 366, 299, 675, 1456

In this list, the two entries that sum to \(2020\) are \(1721\) and \(299\). Multiplying them together produces \(1721 \times 299 = 514579\), so the correct answer is \(514579\).

Assignment

Write a function repair that takes a sequence (list) of positive numbers (Int). The function must return the product (Int) of the two numbers in the sequence that sum to 2020.

Example

> repair [1721, 979, 979, 366, 299, 675, 1456]
514579