Arithmetic

Ever wonder what will happen when you meet a person who uses
a different base system to talk about numbers? For example,
when you hear someone saying this mysterious number `1010110001` (which is in binary), can you
quickly convert it to its decimal form, `689`?

In Harkerland, everyone uses the octal numeral system (base $8$) when talking about numbers. Therefore, new immigrants often have difficulties parsing numbers quickly. One of them is Alex. Alex used to live in a place where the hexadecimal numeral system (base $16$) is adopted. In order to adapt to the Harkerland lifestyle as soon as possible, he trains hard to perform fast octal-to-hexadecimal conversion. Before Alex’s training finishes, he is going to rely on a program for the base conversion. Help Alex write such a program.

Use capital letters `A`, `B`, $\dots
$, `F` to represent the values
$10, 11, \ldots , 15$ in
hexadecimal.

The only line of input consists of a non-negative integer, written in base $8$. The given integer will have no leading zeroes and will be strictly smaller than $8^{200\, 000}$.

Output the same integer, written in base $16$. The output must not include any extra leading zeroes.

For Sample Input 1, $4444_8 = 2340_{10} = 924_{16}$.

Sample Input 1 | Sample Output 1 |
---|---|

4444 |
924 |

Sample Input 2 | Sample Output 2 |
---|---|

20 |
10 |

Sample Input 3 | Sample Output 3 |
---|---|

3211 |
689 |

Sample Input 4 | Sample Output 4 |
---|---|

7654321001234567 |
FAC688053977 |