#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>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll MOD = (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-11;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;
typedef pair<ld, ld> LDP;
int isp[1300]; vector<int> used; int h;
int gcd(int x,int y) {
	if (x < y)swap(x, y);
	while (y) {
		int r = x % y; x = y; y = r;
	}
	return x;
}
int ma = 0;
void sum(int k,int s) {
	if (k == 1)return;
	if (k >= h && isp[k]) {
		sum(k - 1,s); return;
	}
	int len = used.size();
	bool f = true;
	rep(i, len) {
		if (gcd(used[i], k) > 1) {
			f = false;
		}
	}
	if (!f) {
		sum(k - 1,s); return;
	}
	else {
		sum(k - 1, s);
		used.push_back(k);
		sum(k - 1, s + k);
		ma = max(ma, s + k);
		used.pop_back();
		return;
	}
}
int main() {
	fill(isp, isp + 1300, 1);
	Rep(i, 2, 1300) {
		if (isp[i]) {
			for (int j = i * 2; j < 1300; j += i) {
				isp[j] = 0;
			}
		}
	}
	int n; cin >> n; h = n/2 + 1;
	int out = 0;
	for (int i = n; i >= h; i--) {
		if (isp[i])out += i;
	}
	sum(n, 0);
	cout << out + ma << endl;
	return 0;
}