#include <iostream>
#include <sstream>
#include <iomanip>
#include <vector>
#include <string>
#include <map>
#include <set>
#include <algorithm>
#include <numeric>
#include <iterator>
#include <functional>
#include <complex>
#include <queue>
#include <stack>
#include <cmath>
#include <cassert>
#include <cstring>
using namespace std;
typedef long long LL;
typedef complex<double> CMP;

struct UnionFind
{
	vector<int> uf, sz;
	int nc;

	UnionFind(int N): uf(N), sz(N,1), nc(N)
		{ for(int i=0; i<N; ++i) uf[i] = i; }
	int size()
		{ return nc; }
	int Find(int a)
		{ return uf[a]==a ? a : uf[a]=Find(uf[a]); }
	bool Union(int a, int b)
		{
			a = Find(a);
			b = Find(b);
			if( a != b )
			{
				if( sz[a] >= sz[b] ) swap(a, b);
				uf[a] = b;
				sz[b] += sz[a];
				--nc;
			}
			return (a!=b);
		}
};

class CrazyLine { public:
	int maxCrazyness(vector <int> heights) 
	{
		typedef pair< int, pair<int,int> > cand;
		priority_queue<cand> Q;
		for(int i=0; i<heights.size(); ++i)
		for(int j=i+1; j<heights.size(); ++j)
			Q.push( cand(abs(heights[i]-heights[j]), make_pair(i,j)) );

		UnionFind uf(heights.size());

		int score=0;
		vector<int> used(heights.size());
		while( uf.size()>1 )
		{
			int s = Q.top().first;
			int i = Q.top().second.first;
			int j = Q.top().second.second;
			Q.pop();
			if( used[i]<=1 && used[j]<=1 && uf.Find(i)!=uf.Find(j) )
			{
				score += s;
				used[i]++;
				used[j]++;
				uf.Union(i,j);
			}
		}
		return score;
	}
};

// BEGIN CUT HERE
#include <ctime>
double start_time; string timer()
 { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
 { os << "{ ";
   for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
   os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
void verify_case(const int& Expected, const int& Received) {
 bool ok = (Expected == Received);
 if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
 cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
#define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
#define END	 verify_case(_, CrazyLine().maxCrazyness(heights));}
int main(){

CASE(0)
	int heights_[] = {5,10,25,40,25};
	  vector <int> heights(heights_, heights_+sizeof(heights_)/sizeof(*heights_)); 
	int _ = 100; 
END
CASE(1)
	int heights_[] = {2,3,5,7,11,13,17,19};
	  vector <int> heights(heights_, heights_+sizeof(heights_)/sizeof(*heights_)); 
	int _ = 82; 
END
CASE(2)
	int heights_[] = {1,1,1,1,1,1,501};
	  vector <int> heights(heights_, heights_+sizeof(heights_)/sizeof(*heights_)); 
	int _ = 1000; 
END
CASE(3)
	int heights_[] = {1000,1000,1000,1000,1000,1000,1000,1000,1000};
	  vector <int> heights(heights_, heights_+sizeof(heights_)/sizeof(*heights_)); 
	int _ = 0; 
END
/*
CASE(4)
	int heights_[] = ;
	  vector <int> heights(heights_, heights_+sizeof(heights_)/sizeof(*heights_)); 
	int _ = ; 
END
CASE(5)
	int heights_[] = ;
	  vector <int> heights(heights_, heights_+sizeof(heights_)/sizeof(*heights_)); 
	int _ = ; 
END
*/
}
// END CUT HERE
