output_description: Print the minimum positive integer divisible by both 2 and N.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
attempt: import sys, re
  from collections import deque, defaultdict, Counter
  from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
  from itertools import accumulate, permutations, combinations, product, groupby
  from operator import itemgetter, mul
  from copy import deepcopy
  from string import ascii_lowercase, ascii_uppercase, digits
  from bisect import bisect, bisect_left
  from fractions import gcd
  from heapq import heappush, heappop
  from functools import reduce
  
  
  def input():
      return sys.stdin.readline().strip()
  
  
  def INT():
      return int(input())
  
  
  def MAP():
      return map(int, input().split())
  
  
  def LIST():
      return list(map(int, input().split()))
  
  
  def ZIP(n):
      return zip(*(MAP() for _ in range(n)))
  
  
  sys.setrecursionlimit(10**9)
  INF = float("inf")
  mod = 10**9 + 7
  
  N = INT()
  print(2 * N if N % 2 == 0 else N)
  
problem_description: Statement
  
  You are given a positive integer N. Find the minimum positive integer
  divisible by both 2 and N.
samples: [{"input": "3", "output": "6\n    \n\n6 is divisible by both 2 and 3. Also, there is no positive integer less than 6\nthat is divisible by both 2 and 3. Thus, the answer is 6.\n\n* * *"}, {"input": "10", "output": "10\n    \n\n* * *"}, {"input": "999999999", "output": "1999999998"}]