#include <bits/stdc++.h>
#define ll long long
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int x[3], n, ans = 0;
int rez(int n){
    if(n == 1) return 1;
    if(n == 2) return 3;
    int prev = rez(n-1);
    int sol=prev;
    for(int i = 1; i <=n; i++){
        if(gcd(i, n) == 1) sol+=2; 
    }
    return sol;
}
int main(){
    fin >> n;
    fout << rez(n);
    return 0;
}