import math

n = int(eval(input()))

print((2 // math.gcd(2, n) * n))

n = int(eval(input()))

if n % 2 == 0:

    print(n)

else:

    print((2 * n))
import math

n = int(eval(input()))
print((2 // math.gcd(2, n) * n))

n = int(eval(input()))
if n % 2 == 0:
    print(n)
else:
    print((2 * n))

-import math - -print((2 // math.gcd(2, n) * n)) +if n % 2 == 0: +    print(n) +else: +    print((2 * n))