#include <bits/stdc++.h>
using namespace std;
long long int smallestDivisor(long long int n) {
  if (n % 2 == 0) return 2;
  for (long long int i = 3; i * i <= n; i += 2) {
    if (n % i == 0) return i;
  }
  return n;
}
long long int max(long long int a, long long int b) { return a > b ? a : b; }
long long int min(long long int a, long long int b) { return a < b ? a : b; }
long long int gcd(long long int a, long long int b) {
  while (b) {
    long long int t = a;
    a = b;
    b = t % b;
  }
  return a;
}
long long int lcm(long long int a, long long int b) {
  return (max(a, b) / gcd(a, b)) * min(a, b);
}
int cnt[200005] = {0};
vector<int> adj[200005];
map<int, int, greater<int> > factorize(int n) {
  int count = 0;
  map<int, int, greater<int> > fact;
  while (!(n % 2)) {
    n /= 2;
    count++;
  }
  if (count) fact[2] += count;
  for (int i = 3; i <= sqrt(n); i += 2) {
    count = 0;
    while ((n % i) == 0) {
      count++;
      n /= i;
    }
    if (count) fact[i] += count;
  }
  if (n > 2) fact[n]++;
  for (auto it : fact) {
    cnt[it.first]++;
    adj[it.first].push_back(it.second);
  }
  return fact;
}
long long int power(long long int x, int p) {
  if (p == 0) return 1;
  long long int ans = power(x, p / 2);
  ans = ans * ans;
  if (p % 2 == 1) ans = ans * x;
  return ans;
}
bool isPrime(long long int n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (long long int i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
vector<long long int> countDivisors(long long int n) {
  long long int cnt = 0;
  std::vector<long long int> v;
  for (long long int i = 1; i <= sqrt(n); i++) {
    if (n % i == 0) {
      v.push_back(i);
      if (n / i == i)
        cnt++;
      else {
        cnt = cnt + 2;
        v.push_back(n / i);
      }
    }
  }
  return v;
}
bool isPowerOfTwo(long long int x) { return (x && !(x & (x - 1))); }
map<long long int, long long int> factors(long long int n) {
  vector<long long int> f;
  map<long long int, long long int> m;
  for (long long int x = 2; x * x <= n; x++) {
    while (n % x == 0) {
      f.push_back(x);
      m[x]++;
      n /= x;
    }
  }
  if (n > 1) {
    f.push_back(n);
    m[n]++;
  }
  return m;
}
bool cmp(pair<long long int, long long int> v1,
         pair<long long int, long long int> v2) {
  if (v1.first > v2.first) {
    return true;
  } else if (v1.first < v2.first) {
    return false;
  } else {
    return v1.second < v2.second;
  }
}
long long int binarySearch(long long int arr[], long long int l,
                           long long int r, long long int x) {
  if (r >= l) {
    long long int mid = l + (r - l) / 2;
    if (arr[mid] == x) return mid;
    if (arr[mid] > x) return binarySearch(arr, l, mid - 1, x);
    return binarySearch(arr, mid + 1, r, x);
  }
  return -1;
}
int rub[2000001];
bool ispali(int n) {
  int no = n;
  int rev = 0;
  while (no > 0) {
    int ld = no % 10;
    no /= 10;
    rev = rev * 10 + ld;
  }
  if (n == rev)
    return true;
  else
    return false;
}
void np() {
  for (int i = 1; i <= 2000000; i++) {
    if (ispali(i))
      rub[i] = rub[i - 1] + 1;
    else
      rub[i] = rub[i - 1];
  }
}
int pi[20000001];
bool isprime[20000001];
void seive() {
  for (int i = 4; i <= 20000000; i += 2) isprime[i] = 1;
  for (int i = 3; i * i <= 20000000; i += 2) {
    if (!isprime[i]) {
      for (int j = i * i; j <= 20000000; j += i) isprime[j] = 1;
    }
  }
  for (int i = 2; i <= 20000000; i++) {
    if (!isprime[i])
      pi[i] = pi[i - 1] + 1;
    else
      pi[i] = pi[i - 1];
  }
}
int g1;
void bfs(vector<vector<int> > &g, int pos, vector<int> visited) {
  queue<int> q;
  q.push(pos);
  while (q.size() > 0) {
    if (q.front() == g1) {
      cout << "yes";
      return;
    }
    int i = q.front();
    q.pop();
    visited[i] = 1;
    for (int j = 0; j < g[i].size(); j++) {
      if (visited[g[i][j]] == 0) {
        q.push(g[i][j]);
        visited[g[i][j]] = 1;
      }
    }
  }
  return;
}
void pairsort(long long int a[], long long int b[], long long int n) {
  pair<long long int, long long int> pairt[n];
  for (long long int i = 0; i < n; i++) {
    pairt[i].first = a[i];
    pairt[i].second = b[i];
  }
  sort(pairt, pairt + n);
  for (long long int i = 0; i < n; i++) {
    a[i] = pairt[i].first;
    b[i] = pairt[i].second;
  }
}
long long int modpower(long long int x, long long int y, long long int p) {
  long long int res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
long long int modsum(long long int a, long long int b, long long int m) {
  return ((a % m) + (b % m)) % m;
}
long long int modmul(long long int a, long long int b, long long int m) {
  return ((a % m) * (b % m)) % m;
}
long long int modInverse(long long int a, long long int m) {
  return modpower(a, m - 2, m);
}
vector<long long int> factorial() {
  int i;
  vector<long long int> fact(200002 + 1, 0);
  fact[0] = 1;
  for (i = 1; i <= 200002; i++) fact[i] = (fact[i - 1] * i) % 1000000007;
  return fact;
}
long long int highestPowerof2(long long int n) {
  long long int p = (long long int)log2(n);
  return (long long int)pow(2, p);
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int t1 = 1;
  while (t1--) {
    int n;
    cin >> n;
    int a[2 * n];
    for (long long int i = 0; i < 2 * n; i++) cin >> a[i];
    long long int ans = 1000000007;
    sort(a, a + 2 * n);
    for (int i = 0; i < 2 * n; i++) {
      for (int j = 0; j < 2 * n; j++) {
        if (i == j) continue;
        std::vector<int> v;
        for (int k = 0; k < 2 * n; k++) {
          if (k != i && k != j) v.push_back(a[k]);
        }
        int total = 0;
        sort(v.begin(), v.end());
        for (int k = 1; k < v.size(); k += 2) {
          total += v[k] - v[k - 1];
        }
        ans = min(ans, total);
      }
    }
    cout << ans;
  }
  return 0;
}

### Prompt

Generate a Cpp solution to the following problem:

Vadim is really keen on travelling. Recently he heard about kayaking activity near his town and became very excited about it, so he joined a party of kayakers.

Now the party is ready to start its journey, but firstly they have to choose kayaks. There are 2·n people in the group (including Vadim), and they have exactly n - 1 tandem kayaks (each of which, obviously, can carry two people) and 2 single kayaks. i-th person's weight is wi, and weight is an important matter in kayaking — if the difference between the weights of two people that sit in the same tandem kayak is too large, then it can crash. And, of course, people want to distribute their seats in kayaks in order to minimize the chances that kayaks will crash.

Formally, the instability of a single kayak is always 0, and the instability of a tandem kayak is the absolute difference between weights of the people that are in this kayak. Instability of the whole journey is the total instability of all kayaks.

Help the party to determine minimum possible total instability! 

Input

The first line contains one number n (2 ≤ n ≤ 50).

The second line contains 2·n integer numbers w1, w2, ..., w2n, where wi is weight of person i (1 ≤ wi ≤ 1000).

Output

Print minimum possible total instability.

Examples

Input

2
1 2 3 4


Output

1


Input

4
1 3 4 6 3 4 100 200


Output

5

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
long long int smallestDivisor(long long int n) {
  if (n % 2 == 0) return 2;
  for (long long int i = 3; i * i <= n; i += 2) {
    if (n % i == 0) return i;
  }
  return n;
}
long long int max(long long int a, long long int b) { return a > b ? a : b; }
long long int min(long long int a, long long int b) { return a < b ? a : b; }
long long int gcd(long long int a, long long int b) {
  while (b) {
    long long int t = a;
    a = b;
    b = t % b;
  }
  return a;
}
long long int lcm(long long int a, long long int b) {
  return (max(a, b) / gcd(a, b)) * min(a, b);
}
int cnt[200005] = {0};
vector<int> adj[200005];
map<int, int, greater<int> > factorize(int n) {
  int count = 0;
  map<int, int, greater<int> > fact;
  while (!(n % 2)) {
    n /= 2;
    count++;
  }
  if (count) fact[2] += count;
  for (int i = 3; i <= sqrt(n); i += 2) {
    count = 0;
    while ((n % i) == 0) {
      count++;
      n /= i;
    }
    if (count) fact[i] += count;
  }
  if (n > 2) fact[n]++;
  for (auto it : fact) {
    cnt[it.first]++;
    adj[it.first].push_back(it.second);
  }
  return fact;
}
long long int power(long long int x, int p) {
  if (p == 0) return 1;
  long long int ans = power(x, p / 2);
  ans = ans * ans;
  if (p % 2 == 1) ans = ans * x;
  return ans;
}
bool isPrime(long long int n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (long long int i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
vector<long long int> countDivisors(long long int n) {
  long long int cnt = 0;
  std::vector<long long int> v;
  for (long long int i = 1; i <= sqrt(n); i++) {
    if (n % i == 0) {
      v.push_back(i);
      if (n / i == i)
        cnt++;
      else {
        cnt = cnt + 2;
        v.push_back(n / i);
      }
    }
  }
  return v;
}
bool isPowerOfTwo(long long int x) { return (x && !(x & (x - 1))); }
map<long long int, long long int> factors(long long int n) {
  vector<long long int> f;
  map<long long int, long long int> m;
  for (long long int x = 2; x * x <= n; x++) {
    while (n % x == 0) {
      f.push_back(x);
      m[x]++;
      n /= x;
    }
  }
  if (n > 1) {
    f.push_back(n);
    m[n]++;
  }
  return m;
}
bool cmp(pair<long long int, long long int> v1,
         pair<long long int, long long int> v2) {
  if (v1.first > v2.first) {
    return true;
  } else if (v1.first < v2.first) {
    return false;
  } else {
    return v1.second < v2.second;
  }
}
long long int binarySearch(long long int arr[], long long int l,
                           long long int r, long long int x) {
  if (r >= l) {
    long long int mid = l + (r - l) / 2;
    if (arr[mid] == x) return mid;
    if (arr[mid] > x) return binarySearch(arr, l, mid - 1, x);
    return binarySearch(arr, mid + 1, r, x);
  }
  return -1;
}
int rub[2000001];
bool ispali(int n) {
  int no = n;
  int rev = 0;
  while (no > 0) {
    int ld = no % 10;
    no /= 10;
    rev = rev * 10 + ld;
  }
  if (n == rev)
    return true;
  else
    return false;
}
void np() {
  for (int i = 1; i <= 2000000; i++) {
    if (ispali(i))
      rub[i] = rub[i - 1] + 1;
    else
      rub[i] = rub[i - 1];
  }
}
int pi[20000001];
bool isprime[20000001];
void seive() {
  for (int i = 4; i <= 20000000; i += 2) isprime[i] = 1;
  for (int i = 3; i * i <= 20000000; i += 2) {
    if (!isprime[i]) {
      for (int j = i * i; j <= 20000000; j += i) isprime[j] = 1;
    }
  }
  for (int i = 2; i <= 20000000; i++) {
    if (!isprime[i])
      pi[i] = pi[i - 1] + 1;
    else
      pi[i] = pi[i - 1];
  }
}
int g1;
void bfs(vector<vector<int> > &g, int pos, vector<int> visited) {
  queue<int> q;
  q.push(pos);
  while (q.size() > 0) {
    if (q.front() == g1) {
      cout << "yes";
      return;
    }
    int i = q.front();
    q.pop();
    visited[i] = 1;
    for (int j = 0; j < g[i].size(); j++) {
      if (visited[g[i][j]] == 0) {
        q.push(g[i][j]);
        visited[g[i][j]] = 1;
      }
    }
  }
  return;
}
void pairsort(long long int a[], long long int b[], long long int n) {
  pair<long long int, long long int> pairt[n];
  for (long long int i = 0; i < n; i++) {
    pairt[i].first = a[i];
    pairt[i].second = b[i];
  }
  sort(pairt, pairt + n);
  for (long long int i = 0; i < n; i++) {
    a[i] = pairt[i].first;
    b[i] = pairt[i].second;
  }
}
long long int modpower(long long int x, long long int y, long long int p) {
  long long int res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
long long int modsum(long long int a, long long int b, long long int m) {
  return ((a % m) + (b % m)) % m;
}
long long int modmul(long long int a, long long int b, long long int m) {
  return ((a % m) * (b % m)) % m;
}
long long int modInverse(long long int a, long long int m) {
  return modpower(a, m - 2, m);
}
vector<long long int> factorial() {
  int i;
  vector<long long int> fact(200002 + 1, 0);
  fact[0] = 1;
  for (i = 1; i <= 200002; i++) fact[i] = (fact[i - 1] * i) % 1000000007;
  return fact;
}
long long int highestPowerof2(long long int n) {
  long long int p = (long long int)log2(n);
  return (long long int)pow(2, p);
}
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int t1 = 1;
  while (t1--) {
    int n;
    cin >> n;
    int a[2 * n];
    for (long long int i = 0; i < 2 * n; i++) cin >> a[i];
    long long int ans = 1000000007;
    sort(a, a + 2 * n);
    for (int i = 0; i < 2 * n; i++) {
      for (int j = 0; j < 2 * n; j++) {
        if (i == j) continue;
        std::vector<int> v;
        for (int k = 0; k < 2 * n; k++) {
          if (k != i && k != j) v.push_back(a[k]);
        }
        int total = 0;
        sort(v.begin(), v.end());
        for (int k = 1; k < v.size(); k += 2) {
          total += v[k] - v[k - 1];
        }
        ans = min(ans, total);
      }
    }
    cout << ans;
  }
  return 0;
}

```