1008 Elevator (20)（20 分）

The highest building in our city has only one elevator. A request list

is made up with N positive numbers. The numbers denote at which floors

the elevator will stop, in specified order. It costs 6 seconds to move

the elevator up one floor, and 4 seconds to move down one floor. The

elevator will stay for 5 seconds at each stop.

For a given request list, you are to compute the total time spent to

fulfill the requests on the list. The elevator is on the 0th floor at

the beginning and does not have to return to the ground floor when the

requests are fulfilled.

Input Specification:

Each input file contains one test case. Each case contains a positive

integer N, followed by N positive numbers. All the numbers in the input

are less than 100.

Output Specification:

For each test case, print the total time on a single line.

Sample Input:

3 2 3 1

Sample Output:

41