#include<bits/stdc++.h>
using namespace std;

#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define ll long long int
#define ull unsigned long long
#define ld long double

#define mod 1000000007
#define EULER 2.7182818284
#define INF 1000000000

#define pb push_back
#define ins insert
#define IT iterator
#define PQ priority_queue
#define    nl           "\n"
#define fi first
#define se second
#define maxe max_element
#define mine min_element
#define er erase
#define lb lower_bound
#define ub upper_bound

#define vi vector<int>
#define vll vector<ll>
#define vb vector<bool>
#define pi pair<int,int>
#define pll pair<ll,ll>
#define all(v) v.begin(),v.end()
#define mpi map<int,int>
#define mpl map<ll,ll>
#define umpi unordered_map<int,int>
#define umpl unordered_map<ll,ll>
#define si set<int>
#define sl set<ll>
#define msi multi_set<int>
#define msl multi_set<ll>

#define mem(v,i) memset(v,i,sizeof(v)) // v is array. To set all elements to 0 or -1 only. mem(arr,0);


#define repab(i,a,b) for(int i=(a);i<=(b);i++)
#define reprab(i,a,b) for(int i=(a);i>=(b);i--)
#define repll(i,a,b) for(ll i=(a);i<=(b);i++)
#define rep(i,n) for(int i=(0);i<(n);i++)
#define repr(i,n) for(int i=(n);i>=0;i--)
#define bs bitset
#define bpc(a) __builtin_popcount(a)
#define tc int t;cin>>t;while(t--)


int dx[]={1,-1,0,0};
int dy[]={0,0,1,-1};

ll max(ll a,ll b)
{
    if(a>b)return a;return b;
}
ll min(ll a,ll b)
{
    if(a<b)return a;return b;
}

ll mypow(ll a, ll b) {
    ll res = 1;
    while (b > 0) {
        if (b & 1)
            res = res * a;
        a = a * a;
        b >>= 1;
    }
    return res;
}
ll gcd(ll a,ll b)
{
    if(b==0)
    return a;
    return gcd(b,a%b);
}


int main()
{   
    
    fast
    ll n,w;
    cin>>n>>w;
    cout<<n/w<<nl;
    
    return 0;
}
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define reps(i, n) for (int i = 1; i <= (int)(n); i++)
#define all(a) (a).begin(), (a).end()
#define uniq(a) (a).erase(unique(all(a)), (a).end())
#define bit(n) (1LL << (n))
#define dump(a) cerr << #a " = " << (a) << endl
#define fin(a)                                                                                                         \
    cout << (a) << endl;                                                                                               \
    return 0
using vint = vector<int>;
using pint = pair<int, int>;
using vpint = vector<pint>;
template <typename T> using priority_queue_rev = priority_queue<T, vector<T>, greater<T>>;
constexpr double PI = 3.1415926535897932384626433832795028;
constexpr int DY[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0};
constexpr int DX[9] = {1, 0, -1, 0, 1, -1, -1, 1, 0};
int sign(int a) {
    return (a > 0) - (a < 0);
}
int cdiv(int a, int b) {
    return (a - 1 + b) / b;
}
template <typename T> T sq(T a) {
    return a * a;
}
template <typename T, typename U> bool chmax(T &a, const U &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template <typename T, typename U> bool chmin(T &a, const U &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}
template <typename T, typename U> ostream &operator<<(ostream &os, const pair<T, U> &a) {
    os << "(" << a.first << ", " << a.second << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); itr++) {
        os << *itr << (next(itr) != a.end() ? ", " : "");
    }
    os << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const deque<T> &a) {
    os << "(";
    for (auto itr = a.begin(); itr != a.end(); itr++) {
        os << *itr << (next(itr) != a.end() ? ", " : "");
    }
    os << ")";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &a) {
    os << "{";
    for (auto itr = a.begin(); itr != a.end(); itr++) {
        os << *itr << (next(itr) != a.end() ? ", " : "");
    }
    os << "}";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &a) {
    os << "{";
    for (auto itr = a.begin(); itr != a.end(); itr++) {
        os << *itr << (next(itr) != a.end() ? ", " : "");
    }
    os << "}";
    return os;
}
template <typename T, typename U> ostream &operator<<(ostream &os, const map<T, U> &a) {
    os << "{";
    for (auto itr = a.begin(); itr != a.end(); itr++) {
        os << *itr << (next(itr) != a.end() ? ", " : "");
    }
    os << "}";
    return os;
}
struct setup {
    static constexpr int PREC = 20;
    setup() {
        cout << fixed << setprecision(PREC);
        cerr << fixed << setprecision(PREC);
    };
} setup;

signed main() {
    int n;
    cin >> n;
    vint v(2 * n);
    rep(i, 2 * n) cin >> v[i];
    vint a(n), b(n);
    rep(i, n) a[i] = v[n - i - 1];
    rep(i, n) b[i] = v[n + i];
    priority_queue_rev<int> pq;
    int aoki = 0;
    rep(i, n) {
        pq.emplace(a[i]);
        pq.emplace(b[i]);
        aoki += pq.top();
        pq.pop();
    }
    cout << accumulate(all(v), 0LL) - aoki << endl;
}