Black cells in a chessboard Problem Code: BLACKCEL

Given n (n is even), determine the number of black cells in an n×n chessboard

Input Format

The only line of the input contains a single integer n$n$.

Output Format

Output the number of black cells in an n×n$n\times n$ chessboard.

Constraints

• 2≤n≤100$2\le n\le 100$
• n$n$ is even

Sample Input 1 

8

Sample Output 1 

32

Explanation

There are 32$32$ black cells and 32$32$ white cells in an 8×8$8\times 8$ chessboard. So the answer is 32$32$.

import java.util.*;

public class BlackCell {

   

        public static void main(String[] args) throws Exception {

            Scanner sc = new Scanner(System.in);

           

            int n = sc.nextInt();

            System.out.println(n*n/2);

           

            sc.close();

        }

       

}