#include <iostream>
#include <cstdio>
FILE * f = fopen("fractii.in", "r");
FILE * g = fopen("fractii.out", "w");
using namespace std;
int gcd(int a, int b)  
{  
    if (a == 0)  
        return b;  
    return gcd(b % a, a);  
}  
  
 
int phi( int n,int m)  
{  
     int result = 0;  
    for (int i = 1; i <= m; i++)  
        if (gcd(i, n) == 1)  
            result++;  
    return result;  
}  
 
int main( ) {
    int n;
    fscanf(f,"%d", &n);
    int i, result1 ;
    result1 = n + (n+1)/2;
    for (i=3;i<=n;i++) {
        result1 = result1 + n/i * phi(i,i) + phi(i,n%i); 

    }
    fprintf(g,"%d", result1);
    fclose(f);
    fclose(g);
    return 0;
}