Problem Description

There are 200 participants in CODE FESTIVAL 2014, and they are divided into 20 teams numbered from 1 to 20 to participate in a relay race (physical).

The participants are assigned to teams based on their ranking in the main competition, following these steps:

• Participants ranked from 1 to 20 are assigned to teams 1 to 20 in order.
• Participants ranked from 21 to 40 are assigned to teams 1 to 20 in reverse order.
• Participants ranked from 41 to 60 are assigned to teams 1 to 20 in order.
• ...

Given the ranking of a certain participant in the main competition, determine which team this participant belongs to.

Input Format

The input is given in the following format:

$ n $

• The first line contains an integer $ n $ ($1 \leq n \leq 200$), representing the ranking of a participant in the main competition.

Output Format

Output the team number to which the participant with the given ranking is assigned, on a single line.

Ensure that the output ends with a newline and contains no extra characters or blank lines.

Sample Input and Output

Sample Input #1

1

Sample Output #1

1

Sample Input #2

21

Sample Output #2

20

Notes/Hints

None

见题面 Input 部分

见题面 Output 部分