{ Greedy dividing cycles }
{$APPTYPE CONSOLE}
{$B-,R-,O+}
const
 maxn=256;
var
 fi,fo:text;
 n,m,h,i,j,numcol:smallint;
 ans:smallint;
 a:array[1..maxn] of smallint;
 color:array[1..maxn] of smallint;
procedure Search(l,r,h:smallint);
var
 mid,i,j,k:smallint;
begin
 mid:=(l+r)div 2;
 if(r>l)then
  begin
   Search(l,mid,h-1);
   Search(mid+1,r,h-1);
  end;
 for i:=l to mid do
  for j:=mid+1 to r do
   if(color[i]=color[j])then
    begin
     inc(numcol);
     k:=a[i];
     repeat
      color[k]:=numcol;
      k:=a[k];
     until k=a[j];
     inc(ans,h);
     k:=a[i];
     a[i]:=a[j];
     a[j]:=k;
    end;
end;
begin
 assign(fi,'catacomb.dat');
 assign(fo,'catacomb.sol');
 reset(fi);
 rewrite(fo);
 readln(fi,n);
 n:=1 shl n;
 for i:=1 to n do
  read(fi,a[i]);
 m:=1;
 h:=1;
 while(2*m<n) do
  begin
   m:=2*m;
   inc(h);
  end;
 for i:=n+1 to 2*m do
  a[i]:=i;
 numcol:=0;
 fillchar(color,sizeof(color),0);
 for i:=1 to n do
  if color[i]=0 then
   begin
    inc(numcol);
    j:=i;
    repeat
     color[j]:=numcol;
     j:=a[j];
    until j=i;
   end;
 ans:=0;
 Search(1,2*m,h);
 writeln(fo,4*ans);
 close(fi);
 close(fo);
end.