N = int(eval(input()))

if(N%2 == 0):

  print(N)

else:

  print((N*2))
N = int(eval(input()))



def gcd(m, n):

  while n:

    m, n = n, m%n

  return m



def lcm(m, n):

  return int((m * n) / gcd(m, n))



print((lcm(N,2)))
N = int(eval(input()))
if N % 2 == 0:
    print(N)
else:
    print((N * 2))

N = int(eval(input()))


def gcd(m, n):
    while n:
        m, n = n, m % n
    return m


def lcm(m, n):
    return int((m * n) / gcd(m, n))


print((lcm(N, 2)))

-if N % 2 == 0: -    print(N) -else: -    print((N * 2)) + + +def gcd(m, n): +    while n: +        m, n = n, m % n +    return m + + +def lcm(m, n): +    return int((m * n) / gcd(m, n)) + + +print((lcm(N, 2)))