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

#define int long long

#define INF 100000000000000LL

int n;
int y[100010];

int memo[100010][2];

int dp(int i, int x){
    if(i >= n){
        return 0;
    }
    if(i == n-1){
        if(x == 0){
            return INF;
        }else{
            return 0;
        }
    }

    if(memo[i][x] != -1){
        return memo[i][x];
    }

    if(x == 0){
        return memo[i][x] = dp(i+1, 1) + y[i+1]-y[i];
    }else{
        return memo[i][x] = min(dp(i+2, 0) + y[i+1]-y[i], dp(i+1, 0));
    }
}

signed main(){
    cin >> n;
    for(int i = 0;i < n;i++) cin >> y[i];

    sort(y, y+n);

    memset(memo, -1, sizeof(memo));

    cout << dp(0, 0) << endl;
    return 0;
}