#jiaofhaosfhao

n=int(eval(input()))

if(n%2==1):

	n*=2

print(n)
def minDiv():

	N = eval(input())

	N = int(N)

	if N%2 == 0:

		print(N)

	else:

		print((N*2))



minDiv()
# jiaofhaosfhao
n = int(eval(input()))
if n % 2 == 1:
    n *= 2
print(n)

def minDiv():
    N = eval(input())
    N = int(N)
    if N % 2 == 0:
        print(N)
    else:
        print((N * 2))


minDiv()

-# jiaofhaosfhao -n = int(eval(input())) -if n % 2 == 1: -    n *= 2 -print(n) +def minDiv(): +    N = eval(input()) +    N = int(N) +    if N % 2 == 0: +        print(N) +    else: +        print((N * 2)) + + +minDiv()