#include<stdio.h>
int v[10],k;
void gen(double &x){
    int i;
    k=0;
    x=1;
    for(i=1;i<=9;i++)
        v[i]=0;
}
void desc(int x){
    int i=2;
    while(x!=1){
        if(x%i==0)
            v[++k]=i;
        while(x%i==0)
            x/=i;
        i++;
    }
}
int main(){
    int n,s=0,j,i;
    double p;
    freopen("fractii.in","r",stdin);
    freopen("fractii.out","w",stdout);
    scanf("%d",&n);
    for(i=1;i<=n;i++){
        gen(p);
        desc(i);
        p*=n;
        for(j=1;j<=k;j++)
            p*=(1-(1.0/v[j]));
        s+=p;
        if(n%i!=0)
            s++;
    }
    printf("%d",s);
    return 0;
}