Lucky Number 886

Problem Background

Special for beginners, ^_^

Problem Description

In decimal, a number is called a lucky number if it consists only of the digits $6$ and $8$. Sort all lucky numbers in increasing order: the first lucky number is $6$, followed by $8, 66, 68, 86, 88, \dots$

Given $n$, output the $n$-th lucky number.

Input Format

A single integer: $n$.

Output Format

A single integer: the $n$-th lucky number.

Sample Input

7

Sample Output

666

Constraints

1s, 1024KiB for each test case.

$30\%$ of the data: $1 \le n \le 500$

$60\%$ of the data: $1 \le n \le 1,000,000$

$100\%$ of the data: $1 \le n \le 1,000,000,000,000,000$