#include <stdio.h>
#include <stdlib.h>
int n,i,j,nr;
int prime_intre_ele(int a, int b)
{
    while(a!=b)
    {
        if(a>b)
            a=a-b;
        else
            b=b-a;
    }
    return a;
}
int main()
{
    freopen("fractii.in", "r", stdin);
    freopen("fractii.out", "w", stdout);
    scanf("%d",&n);
    nr=2*n-1;
    for(i=2;i<n;i++)
    {
        for(j=i+1;j<=n;j++)
        {
            if(prime_intre_ele(i,j)==1)
            {
                nr+=2;
            }
        }
    }
    printf("%d",nr);
    return 0;
}