hdu 1008(简单数学)

//简单数学题
#include <cstdio>
#include <iostream>

using namespace std;

int main() {
    int n;
    while (scanf("%d", &n), n) {
        int time = 0;
        int one, two;
        one = 0;
        for (int i=0; i<n; ++i) {
            scanf ("%d", &two);
            if (one < two) time += (two - one) * 6;
            else time += (one - two) * 4;
            one = two;
        }
        time += n * 5;
        printf ("%d\n", time);
    }
    return 0;
}