#33039: (●'◡'●)


yp11151230@yphs.tp.edu.tw (909-42蔡亞儒)


#include <iostream>
 
using namespace std;
int main()
{
int d;
while(cin>>d)
{
if(d>0 ) cout<<2*d-1<<endl;
else cout<<-2*d<<endl;
 
 
 
 
}
}