var f,g:text;  
     u,v,j,i,r,nr,n: longint;  
 begin  
 assign(f,'fractii.in');reset(f);  
 assign(g,'fractii.out');rewrite(g);  
 readln(f,n);  
 nr:=1;
 for i:=1 to n-1 do
     for j:=i+1 to n do
         begin  
              u:=i;
              v:=j;  
              repeat  
              r:=u mod v;  
              u:=v;  
              v:=r;  
              until r=0;  
              if u=1 then nr:=nr+2;
         end;  
     writeln(g,nr);  
     close(g);  
     end.