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: # Author: cr4zjh0bp
  # Created: Thu Mar 12 07:37:08 UTC 2020
  import sys
  
  stdin = sys.stdin
  inf = 1 << 60
  mod = 1000000007
  
  ni = lambda: int(ns())
  nin = lambda y: [ni() for _ in range(y)]
  na = lambda: list(map(int, stdin.readline().split()))
  nan = lambda y: [na() for _ in range(y)]
  nf = lambda: float(ns())
  nfn = lambda y: [nf() for _ in range(y)]
  nfa = lambda: list(map(float, stdin.readline().split()))
  nfan = lambda y: [nfa() for _ in range(y)]
  ns = lambda: stdin.readline().rstrip()
  nsn = lambda y: [ns() for _ in range(y)]
  ncl = lambda y: [list(ns()) for _ in range(y)]
  nas = lambda: stdin.readline().split()
  
  
  def gcd(m, n):
      if n == 0:
          return m
      else:
          return gcd(n, m % n)
  
  
  def lcm(m, n):
      return m * n // gcd(m, n)
  
  
  N = ni()
  print(lcm(2, 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"}]