Drone Delivery Total Distance

You are given the number of delivery destinations and their coordinates. Drones dispatch from a central hub (located at coordinate 0) and deliver packages to each destination, then return to the hub. The distance a drone travels for a single delivery is given by:

\(2 \times \text{coordinate}\)

Your task is to compute the total distance traveled by all drones to complete all deliveries.

Note: The input is read from standard input (stdin) and the output should be printed to standard output (stdout).

inputFormat

The first line of input contains an integer n, representing the number of delivery destinations. The following line contains n space-separated integers, each representing the coordinate of a delivery destination.

For example:

3
2 5 8

outputFormat

Output a single integer, the total distance traveled by all drones.

For the sample input above, the output should be:

30

## sample

3
2 5 8

30