Interior Angle Sum of a Polygon

Problem Description

In Euclidean geometry, the sum of interior angles of an $n$-gon ($2 < n \le 1000$) is $(n - 2) \times 180^\circ$. Given $(n - 1)$ of the interior angles, you can compute the remaining unknown angle. Write a program to solve this.

Input Format

The first line contains only one integer $n$. The second line contains $(n - 1)$ positive integers: the degrees of each known interior angle. Adjacent integers are separated by a single space.

The data guarantees the polygon is valid.

Output Format

One positive integer: the degree of the unknown angle.

Sample Input

3
45 60

Sample Output

75

Constraints

$2 < n \le 1000$.

Hint

• Compute $(n - 2) \times 180$, subtract the sum of the given angles, and print the remainder.