#include <cstdio>
int a[101];
int main()
{
    int n;
    while (scanf("%d", &n), n)
    {
        for (int i = 0; i < n; i++)
            scanf("%d", a + i);
        int sum = a[0] * 6 + 5;
        for (int i = 0; i < n - 1; i++)
        {
            if (a[i + 1] > a[i]) sum += (a[i + 1] - a[i]) * 6 + 5;
            if (a[i + 1] < a[i]) sum += (a[i] - a[i + 1]) * 4 + 5;
            if (a[i + 1] == a[i]) sum += 5;
        }
        printf("%d\n", sum);
    }
    return 0;
}