Problem:
Score : 100 points

Problem Statement

You are given a positive integer N.
Find the minimum positive integer divisible by both 2 and N.

Constraints

1 \leq N \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N

Output

Print the minimum positive integer divisible by both 2 and N.

Sample Input 1

3

Sample Output 1

6

6 is divisible by both 2 and 3.
Also, there is no positive integer less than 6 that is divisible by both 2 and 3.
Thus, the answer is 6.

Sample Input 2

10

Sample Output 2

10

Sample Input 3

999999999

Sample Output 3

1999999998

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;
import static java.lang.System.*;
public class Main {
    public static boolean oneFlg = true;
    public static void main(String[] args) throws Exception {
      Scanner sc = new Scanner(System.in);
      int n = sc.nextInt();
      int no;
      for(int i =1;i <= 2*n;i++){
          no = i;
          if(i % 2 ==0 && i % n ==0){
              out.println(i);
          }
      }
        
    }
}