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#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    ifstream fin("input.txt");
    ofstream fout("output.txt");

    int n;
    fin >> n;
    vector<int> vec(n);
    for (int i = 0; i < n; i++) fin >> vec[i];
    sort(vec.begin(), vec.end());
    vector<int> dp(n + 1);
    dp[0] = 0;
    dp[1] = 1000*1000*1000;
    for (int i = 2; i <= n; i++)
        dp[i] = vec[i - 1] - vec[i - 2] + min(dp[i - 1], dp[i - 2]);

    fout << dp[n] << endl;

    fin.close();
    fout.close();
    return 0;
}