#include<cstdio>
#include<set>
#include<algorithm>
#define ittype multiset<int>::iterator
using namespace std;
multiset<int> A;
int main()
{ 
  int sum=0,i,n,t;
  scanf("%d",&n); 
  for (i=1;i<=n;i++)
  {
    if (scanf("%d",&t)==EOF) t=0;
    ittype it=A.insert(t),i1,i2;
    if (i==1) {sum=t;continue;}
    int tmin=1E9;   
    i1=it,i2=it,i2++;
    if (it!=A.begin()) {i1--;tmin=min(tmin,*it-*i1);}
    if (i2!=A.end()) tmin=min(tmin,*i2-*it);
    sum+=tmin;
  }
  printf("%d\n",sum);
}