Honor Guard (Euler function template)

1 Long LongEuler_phi (intN)2 {3     intM= (int) sqrt (n+0.5);4     intans=N;5      for(intI=2; i<=m;i++)6 7         if(n%i==0)8         {9ans=ans/i* (I-1);Ten              while(n%i==0) OneN/=i; A         } -     if(n>1) ans=ans/n* (n1); -     returnans; the}

Description

As a sports Commissioner, C June is responsible for the training of the honor guard. 　　 　　Guard of Honor is composed of students of N * N of the square, in order to ensure that the procession uniform, c June will follow the guard of Honor's left rear, according to the number of students in the line of sight to determine whether the team is neat (such as). Now, C-June wants you to tell him the number of students you can see when the team is neat.

Input

A total of a number n.

Output

A total of a number, that is, c June should see the number of students.

Sample Input

4

Sample Output

9

Hint

"Data size and conventions" for 100% of data, 1≤n≤40000

1#include <iostream>2#include <cstdio>3#include <cstring>4#include <algorithm>5#include <cmath>6#include <sstream>7#include <string>8 using namespacestd;9 Long LongEuler_phi (intN)Ten { One     intM= (int) sqrt (n+0.5); A     intans=N; -      for(intI=2; i<=m;i++) -  the         if(n%i==0) -         { -ans=ans/i* (I-1); -              while(n%i==0) +N/=i; -         } +     if(n>1) ans=ans/n* (n1); A     returnans; at } -  - intMain () - { -     intN; -     Long Longsum=0; inscanf"%d",&n); -      for(intI=1; i<n;i++) tosum+=Euler_phi (i); +sum=sum*2+1; -printf"%lld\n", sum); the     return 0; *}

Honor Guard (Euler function template)