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6228: [洛谷 202406GESP 模拟 一级] 小洛的幸运数字

内存限制：256 MB 时间限制：2 S
题面：传统 评测方式：文本比较 上传者：
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题目描述

A. Almost Prime
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output
A number is called almost prime if it has exactly two distinct prime divisors. For example, numbers 6, 18, 24 are almost prime, while 4, 8, 9, 42 are not. Find the amount of almost prime numbers which are between 1 and n, inclusive.
Input
Input contains one integer number n (1≤n≤3000).
Output
Output the amount of almost prime numbers between 1 and n, inclusive.
Examples
Input 
10
Output 
2
Input 
21
Output 
8

输入样例 复制

输出样例 复制