Task

Let a number be supereven if all of its digits are even(include 0, here we define 0 as even digit).

Here are the first few supereven positive integers:

2, 4, 6, 8, 20, 22, 24, 26, 28, 40, ...

Given an integer n, find the n_th (1-based) supereven positive integer.

Code Limit

Less than 30 characters.

Example

For n = 1, the output should be 2.

1_st supereven positive integer is 2

For n = 5, the output should be 20.

5_th supereven positive integer is 20