1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cmath>
 5 #include <queue>
 6 #include <algorithm>
 7 using namespace std;
 8 int main()
 9 {
10     int n,m,sum,lag;
11     queue<int>mp;
12     while(scanf("%d",&n)&&n)
13     {
14         sum=0;
15         lag=0;
16         for(int i=0;i<n;i++)
17         {
18             scanf("%d",&m);
19             mp.push(m);
20         }
21         while(!mp.empty())
22         {
23             m=mp.front();
24             mp.pop();
25             sum+=abs(m-lag)*((lag-m)>0?4:6);
26             lag=m;
27             sum+=5;
28         }
29         printf("%d\n",sum);
30     }
31     return 0;
32 }