#include"stdio.h"
#include"stdint.h"
#include <cstdlib>
long x;
long out;
struct nod
{
       int n;nod *next;
};nod *a,*b,*c;/*
int_fast32_t cmmdc(int_fast32_t x,int_fast32_t y)
{int b=0;
    while(x&&y)
    {
    switch(b)
    {
    case 0: x%=y;break;
    case 1: y%=x;break;
    }
    b=(b+1)%2;
    }
    if(x)return x;else return y;
}*/
long cmmdc(long x,const long y)
{
     if(y)return cmmdc(y,x%y);
     else return x;
}
int val(const int_fast32_t x,const int_fast32_t y)
{
     if(!x||!y)return 0;
     if(cmmdc(x,y)==1)return 1;
     return 0;
}
int main()
{
    freopen("fractii.out","w",stdout);
    freopen("fractii.in","r",stdin);
    scanf("%ld",&x);
    for(int_fast32_t g=0;g<(x+1)*(x+1)-1;g++){out+=val(g%(x+1),(g+1)/(x+1));}
    printf("%ld",out);
    return 0;
}