#30257: __簡單
#include <iostream>
using namespace std;
int main()
{
int a;
cin>>a;
if(a>0)
cout<<2*a-1<<endl;
if(a<0)
cout<<(-a)*2<<endl;
return 0;
}
#include <iostream>
using namespace std;
int main()
{
int a;
cin>>a;
if(a>0)
cout<<2*a-1<<endl;
if(a<0)
cout<<(-a)*2<<endl;
return 0;
}