#D8407. Multiple of 2 and N
Multiple of 2 and N
Multiple of 2 and N
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.
Examples
Input
3
Output
6
Input
10
Output
10
Input
999999999
Output
1999999998
inputFormat
input are integers.
Input
Input is given from Standard Input in the following format:
N
outputFormat
Output
Print the minimum positive integer divisible by both 2 and N.
Examples
Input
3
Output
6
Input
10
Output
10
Input
999999999
Output
1999999998
样例
9999999991999999998