Slavko is learning about different numeral systems. Slavko is not the brightest when it comes to math, so he is starting out converting binary numerals to octal. The algorithm Slavko uses is this:
 - Pad the binary numeral with zeros on the left until the number of digits is divisible by three.
 - Group adjacent binary digits into groups of $3$ digits.
 - Replace each group of binary digits with the corresponding octal digit (as in Table 1).

000

0

001

1

010

2

011

3

100

4

101

5

110

6

111

7Table 1: Binary to octal 

Write a program that converts a binary numeral to octal so that Slavko can verify his results.

-----Input-----
The input contains a binary numeral. The number of digits will be less than $100$, and the first digit will be $1$.

-----Output-----
Output the number in octal.

-----Examples-----
Sample Input:
1010
Sample Output:
12

Difficulty: introductory

Starter code:

Solutions: