#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int N;
	cin >> N;
	vector<int> Y(N);
	REP(i, N) scanf("%d", &Y[i]);
	sort(ALL(Y));
	
	vector dp(N + 1, INF);
	dp[0] = 0;
	REP(i, N) {
		if (dp[i] == INF) continue;
		if (i + 1 < N) chmin(dp[i + 2], dp[i] + Y[i + 1] - Y[i]);
		if (i + 2 < N) chmin(dp[i + 3], dp[i] + Y[i + 2] - Y[i]);
	}
	cout << dp[N] << endl;
}