#include<fstream>
/*#include<iostream>
#include<conio.h>*/
using namespace std;
int main(){
    fstream in("fractii.in", ios::in);
    fstream out("fractii.out", ios::out);
    unsigned int x,ori;
    int cp,kp;
    in>>x;
    ori=x;
for(int c=2;c<=x;c++){ 
        
ori++; 
//cout<<"ori creste la c="<<c<<" si k="<<1<<" ori devine "<<ori<<endl; 
for(int k=2;k<=x;k++) 

if(c!=k && !(c%2==0 && k%2==0)) { ori++; 
//cout<<"ori creste la c="<<c<<" si k="<<k<<" ori devine "<<ori<<endl; }

}
}
    out<<ori; 



/*getche();*/
return 0;
}