Vasya likes to take a walk in unusual places. One time he stumbled across a beautiful infinite road and, of course, decided to take a walk. Vasya moves along the road with constant speed and passes by several lampposts every hour. It’s notable that exactly at the end of each hour Vasya passed by a lamppost. Let’s call the lampost that Vasya passed by at the end of *i*-th hour the *i*-th *interesting* lamppost.

Lampposts are distributed evenly along the road, and each lamppost has a number assigned to it. Numbers of lampposts are successive integers. Vasya wrote down in his notebook all numbers of interesting lampposts without changing his pace.

A gust of wind ripped out a page that had the number of the *k*-th interesting lamppost. Vasya wants to find out that number, but he can’t remember his speed on the walk along the infinite road. Help Vasya to restore his notes.

### Input

The first and only line contains one integer *k* (0 ≤ *k* ≤ 10^{5}) — end of *k*-th hour.

### Output

Output the number of the *k*-th interesting lamppost.

### Samples

input | output |
---|

2019 | 20191027 |

2020 | 20201101 |

**Problem Author: **Denis Avriskin

**Problem Source: **Ural School Programming Contest 2020