119. Division One
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output
This problem is worth 5 points.

You recently performed well in an online Codeforces contest, and you became part of "Division 1" on Codeforces. However, you're not sure that it will last. If you have a rating of 1900 or higher you're considered Division 1, otherwise, you're considered Division 2.

In each contest after you became Division 1, you didn't perform very well. Thus, your rating will decrease by 50 in each contest. Given your start rating, figure out how many contests it will take for you to become Division 2.

For example, if your start rating was $$$1970$$$, your rating would be $$$1920$$$ after the first contest, and after the second contest your rating would be $$$1870$$$, and you would become Division 2.

Input

The only line of input contains a single positive integer $$$n$$$: your rating after the recent good contest.

Output

Output a single positive integer $$$c$$$: the number of contests that you can still do before you become Division 2.

Examples
Input
1970
Output
2
Input
2035
Output
3
Input
3549
Output
33