a066

/* a066             */
/* AC (17ms, 1.8MB) */
#include <cstdio>
#include <set>
#include <algorithm>

using namespace std;

set<int> Set;
set<int>::iterator up, low;
int in;

int main()
{
    for(int n, sum; ~scanf("%d", &n) && n; sum, Set.clear())
    {
        scanf("%d", &in);
        Set.insert(in);
        sum = in;
        for(int i = 1; i < n && scanf("%d", &in); ++i, Set.insert(in))
        {
            low = Set.lower_bound(in);
            up = low;
            if(low != Set.begin()) --low;
            if(up == Set.end()) sum += in - *low;
            else sum += min(abs(*up - in), abs(in - *low));
        }
        printf("%d\n", sum);
    }
    return 0;
}