Micromasters

Time limit1sMemory limit2048 MB

Summary

Given the number of students Mina referred, each adding a 10% discount, find how many courses she can take for free.

Level: Easy1 of 10
Topics: Math, Implementation
Solved: No attempts yet

Problem

The Department of Computer Engineering at Sharif University of Technology recently started a professional education program called Micromasters. The program offers courses that give students specialized knowledge and skills in several areas of computer science and engineering. To promote the program, the department introduced a referral system. A person who refers another student to Micromasters gets a $10\%$ discount on their own course registrations for each referred student.

Mina is a talented student who wants to spread the benefits of the Micromasters program. Each referral adds to Mina's list of discounts. Given the number of students Mina has referred, find how many courses she can enroll in for free.

Input

The input is a single line containing an integer $n$ ( $0 \le n \le 1000$ ), the number of students Mina has referred.

Output

Print a single line containing the number of courses Mina can enroll in for free using her discounts.

Examples2

Example 1
Input
```
5
```
Expected output
```
0
```
Example 2
Input
```
18
```
Expected output
```
1
```