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-----
3

-----Sample Output-----
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.

Difficulty: introductory

Starter code:

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


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


N = int(input())

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

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

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


N = int(input())

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

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

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

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

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


N = int(input())

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


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

import sys
import math

N = int(input())

print(int((N*2)/math.gcd(N, 2)))

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

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

a=int(input())
b=2
import math
print(int(a*b/math.gcd(a, b)))

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

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

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

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

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

n = int(input())

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


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


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


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

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

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


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


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

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

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

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

#
# abc102 a
#

import sys
from io import StringIO
import unittest


class TestClass(unittest.TestCase):
    def assertIO(self, input, output):
        stdout, stdin = sys.stdout, sys.stdin
        sys.stdout, sys.stdin = StringIO(), StringIO(input)
        resolve()
        sys.stdout.seek(0)
        out = sys.stdout.read()[:-1]
        sys.stdout, sys.stdin = stdout, stdin
        self.assertEqual(out, output)

    def test_入力例_1(self):
        input = """3"""
        output = """6"""
        self.assertIO(input, output)

    def test_入力例_2(self):
        input = """10"""
        output = """10"""
        self.assertIO(input, output)

    def test_入力例_3(self):
        input = """999999999"""
        output = """1999999998"""
        self.assertIO(input, output)


def resolve():
    N = int(input())

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


def __starting_point():
    # unittest.main()
    resolve()

__starting_point()

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

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

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


n = int(input())

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

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

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


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

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

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

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


import math
N = int(input())
def lcm(a,b):
    return int(a*b//math.gcd(a,b))
print(lcm(2,N))

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

n = int(input())

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

n = int(input())
print([n, 2*n][n%2])

from numpy import lcm
n = int(input())
print(lcm(2, n))

N = int(input().rstrip())
if N&1==1:
    print(N*2)
else:
    print(N)


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

def __starting_point():
    main()

__starting_point()

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

#k = int(input())
#s = input()
#a, b = map(int, input().split())
#s, t = map(str, input().split())
#l = list(map(int, input().split()))
#l = [list(map(int,input().split())) for i in range(n)]
#a = [list(input()) for _ in range(n)]
#a = [int(input()) for _ in range(n)]

n = int(input())

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




import math

n = int(input())

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

n = int(input())

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


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

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

a = int(input())

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


n = int(input())

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

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

N = int(input())

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

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


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

a=int(input())
print(a*((a%2)+1))

import math
N = int(input())
print((2*N)//math.gcd(2,N))

num = int(input())

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


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

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


main()

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

# -*- coding: utf-8 -*-

def get_input() -> int:
    """
    標準入力を取得する.

    Returns:\n
        int: 標準入力
    """
    N = int(input())

    return N


def main(N: int) -> None:
    """
    メイン処理.

    Args:\n
        N (int): 正整数(1 <= N <= 10^9)
    """
    # 求解処理
    ans = N
    if ans % 2 != 0:
        ans *= 2

    # 結果出力
    print(ans)


def __starting_point():
    # 標準入力を取得
    N = get_input()

    # メイン処理
    main(N)

__starting_point()

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

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

n = int(input())

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

import math

n = int(input())
gcd = math.gcd(2, n)
lcm = int(2*n/gcd)
ans = lcm

print(ans)

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

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

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

import math

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


import sys

read = sys.stdin.read
readline = sys.stdin.readline
readlines = sys.stdin.readlines
sys.setrecursionlimit(10 ** 9)
INF = 1 << 60
MOD = 1000000007


def main():
    N = int(readline())

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

    return


def __starting_point():
    main()

__starting_point()

N = int(input())

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


# -*- coding: utf-8 -*-
# 標準入力を取得
N = int(input())

# 求解処理
ans = N
if ans % 2 != 0:
    ans *= 2

# 結果出力
print(ans)


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

import sys
import math

#https://atcoder.jp/contests/agc008/submissions/15248942
sys.setrecursionlimit(10 ** 8)
ini = lambda: int(sys.stdin.readline())
inm = lambda: map(int, sys.stdin.readline().split())
inl = lambda: list(inm())
ins = lambda: sys.stdin.readline().rstrip()
debug = lambda *a, **kw: print("\033[33m", *a, "\033[0m", **dict(file=sys.stderr, **kw))

N = ini()

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

import math
n = int(input())
a = math.gcd(n, 2)  # 最大公約数
print(n * 2 // a)

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

N = int(input())

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

import math
a = int(input())
print(a*2//math.gcd(a, 2))

N = int(input())

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

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

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

n = int(input())

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

#
import sys
import math
import numpy as np
import itertools


n = int(input())

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




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

n = int(input())

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

import math
N=int(input())
print(2*N//math.gcd(2,N))

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


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

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

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

N = int(input())

for i in range(2, 10**6):
    if N % 2 == 0:
        break
    N *= i

print(N)

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

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