Problem:
 Score : 100 points    Problem Statement You are given a positive integer N .
Find the minimum positive integer divisible by both 2 and N .      Constraints  1 \leq N \leq 10^9  All values in input are integers.         Input Input is given from Standard Input in the following format:  N       Output Print the minimum positive integer divisible by both 2 and N .        Sample Input 1 3      Sample Output 1 6  6 is divisible by both 2 and 3 .
Also, there is no positive integer less than 6 that is divisible by both 2 and 3 .
Thus, the answer is 6 .       Sample Input 2 10      Sample Output 2 10       Sample Input 3 999999999      Sample Output 3 1999999998

Solution (Python):
N = int(input())
print(N if N%2==0 else N*2)

Solution (Python):
import fractions
a = 2
b = int(input())
f = fractions.gcd(a,b)
f2 = a*b//f
print(f2)

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(N)
else:
  print(N*2)

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

Solution (Python):
n = int(input())

print(n if n%2 == 0 else 2*n)

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

Solution (Python):
N = int(input())
if N % 2:
  print(N * 2)
else:
  print(N)

Solution (Python):
n = int(input())

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

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

Solution (Python):
n = int(input())

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

Solution (Python):
import fractions


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

Solution (Python):
N = int(input())
if N % 2 == 0 : print(N)
else: print(N * 2)

Solution (Python):
N = int( input() )

if N % 2 == 0 : 
   print( N ) 
else : 
   print( N * 2 )

Solution (Python):
n=int(input())
print(2*n if n%2 else n)

Solution (Python):
N = int(input())

if N%2 == 0:
  print(N)
else:
  print(N*2)

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

Solution (Python):
N = int(input())
print(N if N%2 == 0 else N*2)

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

Solution (Python):
import fractions
a=int(input())
print(a * 2 // fractions.gcd(a, 2))

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

Solution (Python):
N=int(input())
if N%2==0:
  print(N)
else:
  print(N*2)

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

Solution (Python):
N = int(input())
print(N * 2 if N % 2 else N)

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

Solution (Python):
n = int(input())
if n % 2:
    print(2 * n)
else:
    print(n)

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

Solution (Python):
N = int(input())

if N % 2:
    print(N * 2)
else:
    print(N)

Solution (Python):
N=int(input())
if N % 2:
  print(N*2)
else:
  print(N)

Solution (Python):
n = int(input())

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

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

Solution (Python):
a=int(input())
print(a+a%2*a)

Solution (Python):
n=int(input())

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

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

Solution (Python):
N=int(input())
print(2*N if N%2!=0 else N)

Solution (Python):
N = int(input())
print(N*(2-(N%2==0)))

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

Solution (Python):
x=int(input())
if x % 2:
  print(2*x)
else:
  print(x)

Solution (Python):
a=int(input())
print(a if a%2==0 else a*2)

Solution (Python):
N = int(input())

if N % 2 == 0:
    ans = N
else:
    ans = N * 2

print(ans)

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

Solution (Python):
n = int(input())

if n >= 2 and n%2 == 0:
    print(n)
else:
    print(2*n)

Solution (Python):
n = int(input())
if n % 2 != 0:
    n *= 2
print(n)

Solution (Python):
N = int(input())
if N % 2 == 0:
    print(N)
else:
    print(2 * N)

Solution (Python):
import fractions


def lcm(x, y):
    return (x * y) // fractions.gcd(x, y)


N = int(input())
print(lcm(N, 2))

Solution (Python):
n = int(input())

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

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

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

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(2 * N)

Solution (Python):
n=int(input());print(n+n%2*n)

Solution (Python):
n=int(input());print(n if n%2==0 else n*2)

Solution (Python):

from fractions import gcd
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

n = int(input())


def lcm_base(a, b):
    return a * b // gcd(a, b)


print(lcm_base(n, 2))

Solution (Python):
n=int(input())
print(n*2 if n%2>0 else n)

Solution (Python):
n = int(input())

if n%2==0:
  print(n)

else:
  print(2*n)

Solution (Python):
def examA():
    N = I()
    if N%2==0:
        ans = N
    else:
        ans = N*2
    print(ans)





import sys,copy,bisect,itertools,heapq,math
from heapq import heappop,heappush,heapify
from collections import Counter,defaultdict,deque
def I(): return int(sys.stdin.readline())
def LI(): return list(map(int,sys.stdin.readline().split()))
def LSI(): return list(map(str,sys.stdin.readline().split()))
def LS(): return sys.stdin.readline().split()
def SI(): return sys.stdin.readline().strip()
mod = 10**9 + 7
inf = float('inf')

examA()

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

Solution (Python):
N=int(input())
if N%2==0:
    print(N)
else:
    print(2*N)

Solution (Python):
N = int(input())
print(N if N % 2 == 0 else N*2)

Solution (Python):
N=int(input())

if N%2==0:
    print(N)
else:
    print(2*N)

Solution (Python):

import sys, math, itertools, heapq, collections, bisect
input = lambda: sys.stdin.buffer.readline().rstrip().decode('utf-8')
sys.setrecursionlimit(10**8)
inf = float('inf')
ans = count = 0

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

Solution (Python):

import sys


def solve(N: int):
    if N % 2 == 0:
        print(N)
    else:
        print(2*N)


def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  
    solve(N)

if __name__ == '__main__':
    main()

Solution (Python):
n = int(input())
print(2*n if n%2 else n)

Solution (Python):


N=int(input())

if N%2==0:
    print(N)
else:
    print(N*2)

Solution (Python):

import math




N = int(input())

if N%2 != 0 :
  N *= 2

print (N)

Solution (Python):
n = int(input())

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

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

Solution (Python):
N = int(input())
if N % 2 == 0:
    print(N)
else:
    print(2 * N)

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

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

Solution (Python):
N = int(input())
if N % 2 == 0:
	print(N)
else:
	print(N*2)

Solution (Python):
x = int(input())

if x%2 == 0:
  print(x)
else:
  print(x*2)

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

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(N)
else:
  print(N * 2)

Solution (Python):
import sys
input = sys.stdin.readline
N = int(input())
if N % 2:
  print(2 * N)
else: print(N)

Solution (Python):
n = int(input())
def gcd(a,b):
  if b == 0:
    return a
  return gcd(b,a%b)
def lcm(a,b):
  return a * b // gcd(a,b)
print(lcm(n,2))

Solution (Python):
N = int(input())
if N % 2 == 1:
    ans = N * 2
else:
    ans = N
print(ans)

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

Solution (Python):
N = int(input())
if N % 2 == 0:
    print(N)
else:
    print(2 * N)

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

Solution (Python):
N = int(input())
print(N if N % 2 == 0 else 2 * N)

Solution (Python):
n = int(input())

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

Solution (Python):
n = int(input())

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

Solution (Python):
_=int(input())
print(_<<(_&1))

Solution (Python):
import math

n = int(input())
asn = 0

if n % 2 == 0: ans = n
else: ans = 2*n

print(ans)

Solution (Python):
a=int(input())
if a%2==0:
  print(a)
else:
  print(2*a)

Solution (Python):

n = int(input())

if n%2==0:
  ret=n
else:
  ret=n*2

print(ret)

Solution (Python):
n= int(input())

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

Solution (Python):
n = int(input())

if n % 2 == 0:
  print(n)
else:
  ans = 2 * n
  print(ans)

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(N*2)

Solution (Python):

import sys, math
input = lambda: sys.stdin.buffer.readline().rstrip().decode('utf-8')
sys.setrecursionlimit(10**8)
inf = float('inf')
ans=count=0


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

Solution (Python):
N = int(input())

if not N % 2:
  print(N)
else:
  print(N * 2)

Solution (Python):
from sys import stdin

n = int(stdin.readline().rstrip())
import fractions
def lcm(x, y):
    return (x * y) // fractions.gcd(x, y)

print(lcm(2,n))

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

Solution (Python):
N = int(input())
print(N*2 if N%2 else N)

Solution (Python):
import fractions

N = int(input())

def lcm(x, y):
  return (x * y) // fractions.gcd(x, y)

print(lcm(2, N))

Solution (Python):
n = int(input())

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

Solution (Python):
n=int(input())
if(n%2):
    print(n*2)
else:
    print(n)

Solution (Python):
n = int(input())
ans=n
if n%2==1:
    ans=2*n
print(ans)

Solution (Python):
N = int(input())

if N % 2 == 0:
    ans = N
else:
    ans = N * 2

print(ans)

Solution (Python):

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

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

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

Solution (Python):
n = int(input())

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

Solution (Python):
n=int(input())
print(n * (2 if n%2 else 1))

Solution (Python):
N = int(input())
if N%2:
    print(2*N)
else:print(N)

Solution (Python):



import sys













def main():
    n = int(sys.stdin.readline().rstrip())
    print(n if n % 2 == 0 else n * 2)


if __name__ == "__main__":
    
    main()

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(N * 2)

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

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

Solution (Python):
N = int(input())

if N % 2 == 0:
  print(N)
else:
  print(N * 2)

Solution (Python):
n = int(input())
ans = n
if n%2:
    ans *= 2
print(ans)

Solution (Python):
n = int(input())
print(n + n * (n % 2))

Solution (Python):
n = int(input())
print(n * 2 // (2 - (n % 2)))

Solution (Python):

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

Solution (Python):
n = int(input().split()[0])

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

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(N*2)

Solution (Python):
a = int(input())
if a%2:
  print(2*a)
else:
  print(a)

Solution (Python):
n = int(input().strip())

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

Solution (Python):
N=int(input())
print(N if N%2==0 else 2*N)

Solution (Python):
a=int(input());print(a*2 if a%2 else a)

Solution (Python):
n = int(input())

if n%2 == 0:
	ans = n
else:
	ans = n*2
	
print(ans)

Solution (Python):
n=int(input())
print(n+n%2*n)

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(N)
else:print(2 * N)

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(N)
else:print(2 * N)

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

Solution (Python):
n=int(input())

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

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

Solution (Python):
n=int(input())

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

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(N)
else:
  print(N*2)

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

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

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

Solution (Python):
n = int(input())
if n % 2:
	print(n*2)
else:
	print(n)

Solution (Python):
n=int(input())
print(2*n if n%2!=0 else n)

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

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(int(2 * N / 2))
else:
  print(int(2 * N))

Solution (Python):
N = int(input())
print(N if N % 2 == 0 else 2*N)

Solution (Python):
N = int(input())
print(N) if N%2 == 0 else print(N*2)

Solution (Python):
N=int(input())
if N%2==0:
  ans=N
else:
  ans=2*N
print(ans)

Solution (Python):
N=int(input())
print(N if N%2==0 else 2*N)

Solution (Python):
n = int(input())

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

Solution (Python):
N=int(input())
print(2*N if N%2!=0 else N)

Solution (Python):
N = int(input())
if N%2 == 0:
  print(N)
else:
  print(2*N)

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

Solution (Python):
N = int(input())

if N % 2 == 0:
    ans = N
else:
    ans = N * 2

print(ans)

Solution (Python):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

N = int(read())

if N&1: N += N
print(N)

Solution (Python):
n = int(input())

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

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

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

Solution (Python):
n = int(input())
print(n+n % 2*n)

Solution (Python):
N  =int(input())

if N%2==0:
    print(N)
else:
    print(N*2)

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

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

Solution (Python):
n=int(input())
print(n*2 if n&1 else n)

Solution (Python):
N = int(input())
if (N%2==0):
  print(N)
else :
  print(N*2)

Solution (Python):
N = int(input())
if N % 2 == 1:
    print(2*N)
else:
    print(N)

Solution (Python):
n = int(input())

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

Solution (Python):
N = int(input())

if N % 2 == 0:
  print(N)
else:
  print(2 * N)

Solution (Python):
a=int(input())
if a%2==0:
    print(a)
else:
    print(a*2)

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

Solution (Python):

N = int(input())

if N%2==0:
    print(N)
else:
    print(2*N)

Solution (Python):


N = int(input())

if(N %2 != 0):
    print(N*2)
elif(N%2 == 0):
    print(N)

Solution (Python):
N = int(input().strip())
if N % 2 == 0:
    print(N)
else:
    print(N*2)

Solution (Python):

N = int(open(0).read())
i = 0
while(N*i <= 10**9):
    i+=1
    
    if (N*i)%2 == 0:
        print(N*i)
        break

Solution (Python):
n = int(input())
while True:
    if n%2 == 0:
        print(n)
        break
    n+=n

Solution (Python):
n = int(input())
if n % 2 == 0:
    print(n)
elif n % 2 != 0:
    print(2 * n)

Solution (Python):
s=int(input())
if s%2==0:
  print(s)
else:
  print(2*s)

Solution (Python):
N = int(input())

if N % 2 == 0 :
    print(N)
else :
    print(2 * N)

Solution (Python):
N = int(input())

if N % 2 == 0:
  print(N)
else:
  print(N*2)

Solution (Python):
s=int(input())
print(s if s%2==0 else s*2)

Solution (Python):
n = int(input())

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

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

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

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

Solution (Python):
N=int(input())

if N % 2==0:
  print(N)
else:
  print(2 * N)

Solution (Python):
N = int(input())

if N % 2 == 0:
  print(N)
else:
  print(N*2)

Solution (Python):
n = int(input())



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

Solution (Python):
N = int(input())    
if(N%2==0):
    ans=N
else:
    ans=2*N
print(ans)

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

Solution (Python):

from fractions import gcd
n=int(input())
def lcm(m,n):
    return (m*n)//gcd(m,n)
print(lcm(2,n))

Solution (Python):
n = int(input())

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

Solution (Python):
N=int(input())

if N%2==0:
  print(N)
else:
  print(N*2)

Solution (Python):
N = int(input())

if N%2==0:
    print(N)
else:
    print(N*2)

Solution (Python):
N = int(input())
if N % 2 == 0:
    print(N)
else:
    print(N * 2)

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(N*2)

Solution (Python):
'''A - Multiple of 2 and N
https://atcoder.jp/contests/abc102/tasks/abc102_a

>>> main(3)
6
>>> main(10)
10
>>> main(999999999)
1999999998'''


def main(n):
    if n % 2 == 0:
        print(n)
    else:
        print(n*2)


if __name__ == "__main__":
    n = int(input())

    main(n)

Solution (Python):
n=int(input())
print(n+n%2*n)

Solution (Python):
a = int(input())
i=1
if a%2==0 and a%a==0:
  print(a)
else:
 print(a*2)

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

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

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

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

Solution (Python):
N = int(input())

if N % 2 != 0:
    print(str(2 * N))
else:
    print(str(N))

Solution (Python):
N=int(input())
if N % 2 == 0:
  print(N)
else:
  print(N*2)

Solution (Python):
N = int(input())
if(N%2==0):
    print(N)
else:
    print(2*N)

Solution (Python):
n = int(input())

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

Solution (Python):
def slove():
    import sys
    import fractions
    input = sys.stdin.readline
    n = int(input().rstrip('\n'))
    print(2 * n // fractions.gcd(n, 2))


if __name__ == '__main__':
    slove()

Solution (Python):
import sys
import math

input = sys.stdin.readline


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


if __name__ == "__main__":
    main()

Solution (Python):
N = int(input())
print(N if N%2==0 else 2*N)

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

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

Solution (Python):
n=int(input())

if n%2:
  print(2*n)
else:
  print(n)

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

Solution (Python):
N = int(input())

print(N * 2 if N % 2 == 1 else N)

Solution (Python):
n = int(input())
if n % 2 != 0:
  print(2*n)
else:
  print(n)

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

Solution (Python):
a = int(input())
if a % 2 == 0:
  print(a)
else:
  print(a*2)

Solution (Python):
N=int(input());print(N+N*(int(N%2!=0)))

Solution (Python):
N = int(input())

if N % 2 == 0 :
  print(N)
  
else:
  print( 2 * N )

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

Solution (Python):
n = int(input())

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

Solution (Python):
n = int(input())
print(n if n%2==0 and n%n==0 else n*2)

Solution (Python):
N = int(input())
if N==1:
    x = 2
elif N%2==0:
    x = N
else:
    x = 2*N
print(x)

Solution (Python):
x=int(input())
if x%2==0:
  print(x)
else:
  print(2*x)

Solution (Python):
n = int(input())
if n % 2 == 1:
    print(n*2)
else:
    print(n)

Solution (Python):
N = int(input())

if N % 2 == 0:
  print(N)
else:
  print(N*2)

Solution (Python):
N = int(input())
if N%2==1:
  print(N*2)
else:
  print(N)

Solution (Python):
N=int(input())

if N%2==0:
    print(N)
else:
    print(2*N)

Solution (Python):
N = int(input())
if N % 2 == 0:
	print(N)
else:
	print(2*N)

Solution (Python):
N = int(input())

if N%2==0:
  print(N)
else:
  print(N*2)

Solution (Python):
N=int(input())
if N%2==0:
    ans=N
else:
    ans=N*2
print(ans)

Solution (Python):
n=int(input())

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

Solution (Python):
n=int(input());print(n if n%2==0 else n*2)

Solution (Python):
N=int(input())
if N%2==0:
  print(N)
else:
  print(N*2)

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

Solution (Python):
n = int(input())

if n%2:
  print(2*n)
else:
  print(n)

Solution (Python):
N = int(input())
if N%2 == 0:
    print(N)
else:
    print(2*N)

Solution (Python):
n = int(input())

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

Solution (Python):
N = int(input())

if N % 2 == 1:
    print(N*2)
    
else:
    print(N)

Solution (Python):
N = int(input())
if N%2 == 0:
     print(N)
else:
    print(2*N)

Solution (Python):
N = int(input())
[print(N) if N%2 == 0 else print(N*2)]

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

Solution (Python):
n=int(input())
print(2*n if n%2 else n)

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

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(2 * N)

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

Solution (Python):
n = int(input())

print(2*n if n%2 == 1 else n)

Solution (Python):
N = int(input())
ans = 0
if N <= 2:
    ans = 2
else:
    if N%2 == 0:
        ans = N
    else:
        ans = N*2
print(ans)

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

Solution (Python):



def main():

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




if __name__ == "__main__":
    main()

Solution (Python):

from fractions import gcd
n = int(input())
print(2 * n // gcd(2, n))

Solution (Python):
N = int(input())
print(2*N if N%2==1 else N)

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

Solution (Python):
N=int(input())
def gcd(a,b):
  if a==b:
    return a
  else:
    a,b=max(a,b),min(a,b)
    if a%b==0:
      return b
    return gcd(b,a%b)  
lcm=int(2*N/gcd(2,N))
print(lcm)

Solution (Python):
N=int(input())
def gcd(a,b):
  if a==b:
    return a
  else:
    a,b=max(a,b),min(a,b)
    if a%b==0:
      return b
    return gcd(b,a%b)  
if N%2==0:
  print(N)
else:
  lcm=int(2*N/gcd(2,N))
  print(lcm)

Solution (Python):
N=int(input())
if N%2==0:
  print(N)
else:
  lcm=2*N
  print(lcm)

Solution (Python):
N = int(input())
print(N+N%2*N)

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

Solution (Python):
import sys

if sys.platform =='ios':
    sys.stdin=open('input_file.txt')

N=int(input())

if N%2==0:
	N=N//2

print(N*2)

Solution (Python):
n = int(input())
print(2*n if n%2 else n)

Solution (Python):
n = int(input())

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

Solution (Python):
N = int(input())

def gcd(a,b):
  while b:
    a,b = b, a%b
  return a

print(N*2//gcd(N, 2))

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

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

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

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

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

Solution (Python):
N = int(input())
if N % 2 ==0:
  print(N)
  exit()
print(2*N)

Solution (Python):

n = int(input())

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

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

Solution (Python):
n=int(input())

if n==1:
    print(2)
elif n%2==0:
    print(n)
else:
    print(2*n)

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

Solution (Python):
s=int(input())
start=s*2
if s%2==0:
  start=int(start/2)
print(start)

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(N*2)

Solution (Python):
n=int(input());print(n*2 if n%2 else n)

Solution (Python):
N=int(input())
print([N,2*N][N%2])

Solution (Python):
import fractions
n = int(input())
gcd = fractions.gcd(2, n)
lcm = 2 * n // gcd
print(lcm)

Solution (Python):
N=int(input())
print(2*N if N%2==1 else N)

Solution (Python):
i = int(input())

if i % 2== 0:
  print(i)
else:
  print(i*2)

Solution (Python):
N = int(input().strip())
if N % 2 == 0:
  print(N)
else:
  print(2*N)

Solution (Python):
n = int(input())
print(n*2) if n%2 else print(n)

Solution (Python):

n = int(input())
print(n*2 if n%2 == 1 else n)

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

Solution (Python):
n = int(input())
print(2*n if n%2 else n)

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

Solution (Python):
N = int(input())

if N%2 == 0:
    print(N)
else:
    print(2*N)

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

Solution (Python):
n=int(input())
print(n*2 if n%2==1 else n)

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

Solution (Python):
N = int(input())

if N % 2 == 0:
    print(N)
else:
    print(2 * N)

Solution (Python):
n=int(input())
print(2*n if n%2 else n)

Solution (Python):
N = int(input())

if N%2 == 0:
    print(N)
else:
    print(N*2)

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

Solution (Python):
N=int(input())
print(N*(1+(N%2==1)))

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

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

Solution (Python):
n = int(input())
if n == 2 or n == 1:
    print(2)
elif n % 2 == 1:
    print(n * 2)
else:
    print(n)

Solution (Python):
N = int(input())
if N % 2 == 0:
    print(N)
else:
    print(2 * N)

Solution (Python):
n = int(input())

if n % 2:
    print(2 * n)
else:
    print(n)

Solution (Python):
N = int(input())
if N%2==0:
  print(N)
else:
  print(N*2)

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(N)
else:
  print(N*2)

Solution (Python):
N =int(input())
print(N*(N%2+1))

Solution (Python):
n = int(input())
while True:
    if n % 2 == 0:
        print(n)
        break
    n += n

Solution (Python):
N = int(input())
if N%2 == 0:
  r = N
else:
  r = 2*N
print(r)

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

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

Solution (Python):
n=int(input())
print(n*2 if n%2 else n)

Solution (Python):
N = int(input())

if N&1:
    print(N*2)
else:
    print(N)

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

Solution (Python):
n = int(input())
if 1 <= n <= 10 ** 9:
    if 0 == n % 2:
        print(n)
    else:
        print(n * 2)
else:
    print('hoge!')

Solution (Python):
N = int(input())
index = 1
while True:
    if N % 2 == 0 and N % N == 0:
        print(N)
        break
    else:
        index += 1
        N = index * N

Solution (Python):
n = int(input())
print(2*n if n%2 else n)

Solution (Python):
num = int(input())
if num%2==0:
  print(num)
else:
  print(num*2)

Solution (Python):
s = int(input())
if int(s%2):
    print(2*s)
else:
    print(s)

Solution (Python):
import sys
from collections import deque
stdin = sys.stdin

ni = lambda: int(ns())
na = lambda: list(map(int, stdin.readline().split()))
ns = lambda: stdin.readline()

n = ni()
print(2 * n if n % 2 != 0 else n)

Solution (Python):
N=int(input())
if(N%2 == 0):
    print(N)
else:
    print(2*N)

Solution (Python):
a=int(input());print(a*2 if a%2 else a)

Solution (Python):
n = int(input())
print(n*(1+n%2))

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

Solution (Python):
from fractions import gcd


def lcm(a, b):
    return a * b  // gcd(a, b)


n = int(input())
print(lcm(2, n))

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

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

Solution (Python):
n = int(input())
if n%2 == 0:
  print(n)
elif n%2 ==1:
  print(2*n)

Solution (Python):
N=int(input())
if N%2==0:
  print(N)
else:
  print(2*N)

Solution (Python):

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

Solution (Python):
n=int(input())

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

Solution (Python):
N = int(input())

if N%2==0:
  print(N)
else:
  print(2*N)

Solution (Python):
import fractions
N = int(input())
print(int((2*N) / fractions.gcd(2,N)))

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

Solution (Python):
N=int(input())
if N%2==0:
    print(N)
else:
    print(2*N)

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

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

Solution (Python):
N=int(input())

print(N if N%2==0 else N*2)

Solution (Python):
n = int(input())
print(2 * n if n % 2 == 1 else n)

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

Solution (Python):
n = int(input())
if n%2:
  print(n*2)
else:
  print(n)

Solution (Python):
N = int(input())
print(N if N%2==0 else 2*N)

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

Solution (Python):
N = int(input())
print([N,N*2][N%2])

Solution (Python):
N=int(input())
print(N if N%2==0 else N*2)

Solution (Python):
n=int(input());print(n*2if n%2else n)

Solution (Python):
import math
import sys
import queue
from collections import Counter
from itertools import accumulate
from fractions import gcd
from functools import reduce

def lcm(a, b):
    return a * b // gcd(a, b)

def combination_count(n, r):
    return math.factorial(n) // (math.factorial(n - r) * math.factorial(r))

def permutations_count(n, r):
    return math.factorial(n) // math.factorial(n - r)

mod = 1000000007

"""


    = sys.stdin.readline().rstrip()
    = list(sys.stdin.readline().rstrip())


    = int(sys.stdin.readline())
    = map(int, sys.stdin.readline().split())
    = list(map(int, sys.stdin.readline().split()))
    = [list(map(int,list(sys.stdin.readline().split()))) for i in range(N)]
"""

if __name__ == "__main__":
    N = int(sys.stdin.readline())
    print(lcm(2, N))

Solution (Python):
N = int(input())

if N%2==0:
  print(N)
else:
  print(2*N)

Solution (Python):
a = int(input())

if a % 2 == 0:
  print(a)
else:
  print(2*a)

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

Solution (Python):
N = int(input())
print(N if N%2==0 else 2*N)

Solution (Python):
n = int(input())
print(2*n if n%2 else n)

Solution (Python):
n = int(input())
print(n * 2 if n % 2 else n)

Solution (Python):
N = int(input())
if N%2==0:
  print(N)
else:
  print(2*N)

Solution (Python):
import fractions
N = int(input())
print(N*2//fractions.gcd(N,2))

Solution (Python):
N = int(input())
print(N) if N % 2 == 0 else print(N * 2)

Solution (Python):
def main():
    N = int(input())
    if N % 2 == 0: return N
    else: return N*2

if __name__ == '__main__':
    print(main())

Solution (Python):
N = int(input())
print(N) if N%2 == 0 else print(2*N)

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

Solution (Python):
n = int(input())

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

Solution (Python):
N = int(input())
if N % 2 == 0:
  print(N)
else:
  print(N*2)

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

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

Solution (Python):
n = int(input())

num = n
cnt = 1
while True:
    if num % 2 == 0 and num % n == 0:
        print(num)
        exit(0)
    cnt += 1
    num = n * cnt