#include <fstream>

using namespace std;

ifstream cin ("fractii.in");
ofstream cout ("fractii.out");

int n,fact[50],l,S;

void desc (int n)
{
    int x=n;
    if (x%2==0) {
        fact[++l]=2;
        while (x%2==0) x/=2;
    }
    int k=3;
    while (x>1){
        if(x%k==0){
            fact[++l]=k;
            while(x%k==0) x/=k;
        }
        k+=2;
    }
}

int main()
{
    cin>>n;
    for (int i=1; i<=n; ++i)
    {
        l=0;
        int s=n;
        desc(i);
        for (int i=1; i<=l; ++i) s-=n/fact[i];
        for (int i=1; i<=l; ++i)
            for (int j=i+1; j<=l; ++j)
                s+=n/fact[i]*fact[j];
        S+=s;
    }
    cout<<S;
    return 0;
}