#include <iostream>
int main()
{
int n;
std::cin >> n;
std::cout << n + 1 + n % 2 << std::endl;
system("pause");
return 0;
}
#include <iostream>
int main()
{
int n;
std::cin >> n;
std::cout << n + 1 + n % 2 << std::endl;
system("pause");
return 0;
}