#include <stdio.h>

int cmmdc(int a, int b)
{
    int t;
    while(b!=0)
    {
        t=b;
        b=a%b;
        a=t;
    }
    return a;
}

int main()
{
    freopen("fractii.in","r",stdin);
    freopen("fractii.out","w",stdout);
    int n,s=1,i,j;
    scanf("%d",&n);
    for (i=1; i<n; i++)
        for (j=i+1; j<=n; j++)
            if (cmmdc(i,j)==1) s=s+2;
    printf("%d",s);
}