import fractions

n=int(eval(input()))

print(((2*n)//fractions.gcd(2,n)))
N=int(eval(input()));print((N if N%2==0 else N*2))
import fractions

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

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

-import fractions - -n = int(eval(input())) -print(((2 * n) // fractions.gcd(2, n))) +N = int(eval(input())) +print((N if N % 2 == 0 else N * 2))