Codeforces 630K Indivisibility【容斥】

K. Indivisibility

time limit per test
0.5 seconds

memory limit per test
64 megabytes

input
standard input

output
standard output

IT City company developing computer games decided to upgrade its way to reward its employees. Now it looks the following way. After a new game release users start buying it actively, and the company tracks the number of sales with precision to each transaction.
Every time when the next number of sales is not divisible by any number from 2 to 10 every
developer of this game gets a small bonus.

A game designer Petya knows that the company is just about to release a new game that was partly developed by him. On the basis of his experience he predicts that n people
will buy the game during the first month. Now Petya wants to determine how many times he will get the bonus. Help him to know it.

Input

The only line of the input contains one integer n (1 ≤ n ≤ 1018)
— the prediction on the number of people who will buy the game.

Output

Output one integer showing how many numbers from 1 to n are
not divisible by any number from 2 to 10.

Examples

input

12

output

2

从1 到n 有多少数不能被从2到10的数整除，容斥原理

#include <iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<vector>
#include<queue>
#include<stack>
#include<algorithm>
using namespace std;
int main()
{
long long n,sum;
while(~scanf("%I64d",&n))
{
sum=n/2+n/3+n/5+n/7-n/6-n/10-n/14-n/15-n/21-n/35+n/30+n/42+n/70+n/105-n/210;
sum=n-sum;
printf("%I64d\n",sum);
}
return 0;
}