The guard of Honor asks for the value of Euler function within n

I-Honor GuardTime limit:10000MS Memory Limit:265216KB 64bit IO Format:%lld &%llu SubmitStatus

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

#include <iostream> #include <cstdio> #include <string> #include <cstring> #include <cmath > #include <sstream> #define N 50900using namespace Std;typedef long long ll;int vis[n],pri[n];int cnt;void init ()    {cnt=0;        for (int i=2;i<=n;i++) {if (vis[i]==0) pri[cnt++]=i;            for (int j=0;j<cnt && i*pri[j]<n;j++) {vis[i*pri[j]]=1;        if (i%pri[j]==0) break;    }}}int Main () {int n;    Init ();            while (~SCANF ("%d", &n)) {if (n==1) {puts ("1");        Continue        }//for (int i=0;i<100;i++)//cout<<pri[i]<< "";        int num;        int ans=0;            for (int i=1;i<n;i++)//n Euler function {num=i;            for (int j=0;j<cnt && pri[j]<=40009;j++) if (i%pri[j]==0) num=num* (pri[j]-1)/pri[j];            cout<< "num=" <<num<<endl;        Ans+=num;      }  printf ("%d\n", ans*2+1); } return 0;}

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The guard of Honor asks for the value of Euler function within n