#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<complex>
#include<bitset>
#include<stack>
#include<unordered_map>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = (ll)(1e+9) + 7;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
typedef long double ld;
typedef complex<ld> Point;
const ld eps = 1e-12;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;
typedef pair<ld, ld> LDP;
int deq[1263]; int t;
int ma; int n;
bool check(int a, int b) {
	if (a < b)swap(a, b);
	while (b) {
		int r = a % b; a = b; b = r;
	}
	if (a == 1)return true;
	else return false;
}
void dfs(int num, int sum) {
	if (num == n + 1)return;
	bool valid = true;
	rep(i, t)if (!check(num, deq[i]))valid = false;
	ma = max(ma, sum);
	dfs(num + 1, sum);
	if (valid) {
		ma = max(ma, sum + num);
		deq[t] = num; t++;
		dfs(num + 1, sum + num);
		t--;
	}
}
int main() {
	cin >> n; dfs(2,0); cout << ma << endl;
	return 0;
}