#include<stdio.h>

void read(),solve();

long n,d,sol,a;

int main()
{   read();
    solve();

    return 0;
}

void read()
{    freopen("fractii.in","r",stdin);
     freopen("fractii.out","w",stdout);
     scanf("%ld",&n);
}

void solve()
{    sol=n*n;
     for(a=2;a<=n;a++)
     {   for(d=2;d<a;d++)
            if(a%d==0) sol--;
         sol-=n/a;
     }
}