You cannot submit for this problem because the contest is ended. You can click "Open in Problem Set" to view this problem in normal mode.

Description

In Euclidean geometry, the sum of interior angles of an n-sided polygon is (n-2)×180°.
Given (n-1) interior angles of an n-sided polygon, write a program to calculate the remaining unknown interior angle.

Input Format

The first line contains a single integer n (3≤n≤20).
The second line contains (n-1) positive integers representing the known interior angles, separated by spaces. The input guarantees that the polygon is valid.

Output Format

Output a single positive integer representing the unknown interior angle.

Sample

3
45 60

75