题目描述
A greek once sifted some numbers. And it did something wonderful!
-----Input:-----
- First line will contain an integer $N$
-----Output:-----
Output in a single line answer to the problem.
-----Constraints-----
- $1 \leq N \leq 10^5$
-----Sample Input 1:-----
10
-----Sample Output 1:-----
4
-----Sample Input 2:-----
20
-----Sample Output 2:-----
8
输入格式
见题面
输出格式
见题面
样例输入
['10']
样例输出
['4']