#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
template<class T> inline void YES(T condition){ if(condition) cout << "YES" << endl; else cout << "NO" << endl; }
template<class T> inline void Yes(T condition){ if(condition) cout << "Yes" << endl; else cout << "No" << endl; }
template<class T> inline void POSS(T condition){ if(condition) cout << "POSSIBLE" << endl; else cout << "IMPOSSIBLE" << endl; }
template<class T> inline void Poss(T condition){ if(condition) cout << "Possible" << endl; else cout << "Impossible" << endl; }
template<class T> inline void First(T condition){ if(condition) cout << "First" << endl; else cout << "Second" << endl; }
int character_count(string text, char character){ int ans = 0; for(int i = 0; i < text.size(); i++){ ans += (text[i] == character); } return ans; }
long power(long base, long exponent, long module){ if(exponent % 2){ return power(base, exponent - 1, module) * base % module; }else if(exponent){ long root_ans = power(base, exponent / 2, module); return root_ans * root_ans % module; }else{ return 1; }}
struct position{ int y, x; }; position move_pattern[4] = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}}; // double euclidean(position first, position second){ return sqrt((second.x - first.x) * (second.x - first.x) + (second.y - first.y) * (second.y - first.y)); }
template<class T, class U> string to_string(pair<T, U> x){ return to_string(x.first) + "," + to_string(x.second); }
template<class itr> void array_output(itr start, itr goal){ string ans; for(auto i = start; i != goal; i++){ ans += to_string(*i) + " "; } ans.pop_back(); cout << ans << endl; }
template<class T> T gcd(T a, T b){ if(a && b){ return gcd(min(a, b), max(a, b) % min(a, b)); }else{ return a; }} template<class T> T lcm(T a, T b){ return a / gcd(a, b) * b; }
#define mod long(1e9 + 7)
#define all(x) (x).begin(), (x).end()
#define bitcount(n) __builtin_popcountl(long(n))
#define fcout cout << fixed << setprecision(10)
#define highest(x) (63 - __builtin_clzl(x))


int N;
vector<int> primes = {2, 3, 5, 7, 11, 13, 17, 19, 23, 29};

vector<int> maximum_on_set;

int divide(int now, vector<int> now_array_BIT){
    if(now == primes.size()){
        int ans = 0;
        for(int i = 0; i < now_array_BIT.size(); i++){
            ans += maximum_on_set[now_array_BIT[i]];
        }
        return ans;
    }
    int ans = 0;
    for(int i = 0; i < now_array_BIT.size(); i++){
        now_array_BIT[i] += (1 << now);
        ans = max(ans, divide(now + 1, now_array_BIT));
        now_array_BIT[i] -= (1 << now);
                  
    }
    now_array_BIT.push_back(1 << now);
    ans =  max(ans, divide(now + 1, now_array_BIT));
   // cout << ans << endl;
    return ans;
}

vector< bool > get_prime(int n){
    vector< bool > prime( n + 1, true);
    
    if(n >= 0) prime[0] = false;
    if(n >= 1) prime[1] = false;
    
    for(int i = 2; i * i <= n; i++){
        if(prime[i]){
            for(int j = i + i; j <= n; j += i) prime[j] = false;
        }
    }
    
    return(prime);
}

int main(){
    cin >> N;
    while(primes.back() > N){
        primes.pop_back();
    }
    maximum_on_set.push_back(0);
    for(int i = 1; i < (1 << primes.size()); i++){
        for(int j = N; j > 1; j--){
            int tmp_j = j;
            for(int k = 0; k < primes.size(); k++){
                if((i >> k) & 1){
                    while(tmp_j % primes[k] == 0){
                        tmp_j /= primes[k];
                    }
                }
            }
            if(tmp_j == 1){
                maximum_on_set.push_back(j);
                break;
            }
        }
    }
    int ans = divide(0, {});
    auto prime_array = get_prime(N);
    for(int i = 30; i <= N; i++){
        ans += prime_array[i] * i;
    }
    cout << ans << endl;
}