51nod 1284 2 3 5 7的倍数（容斥）

输入1个数N(1 <= N <= 10^18)。

输出不是2 3 5 7的倍数的数共有多少。

10

1

//容斥
import java.util.*;
import java.math.*;

public class Main{
public static void main(String [] args){
Scanner in = new Scanner(System.in);
long n = in.nextLong();
long a = n/2,b = n/3,c = n/5,d = n/7;
long ab = n/6,ac = n/10,ad = n/14,bc = n/15,bd = n/21,cd = n/35;
long abc = n/30,abd = n/42,acd = n/70,bcd = n/105;
long abcd = n/210;
long res = a+b+c+d-(ab+ac+ad+bc+bd+cd)+(abc+abd+acd+bcd)-abcd;
System.out.println(n-res);
}
//static void fun(int n){

//}
}