Program fractii;
type nat=0..1000000;
var n,i,j,nr:nat;
    f,g:text;
Function sim(x,y:nat):boolean;
var k:boolean;d:nat;
begin
  k:=true;
  if x<y then
  begin
    d:=2;
    while (d<=x) and (k=true) do
    begin
      if (x mod d=0) and (y mod d=0) then k:=false;
      inc(d);
    end;
  end
         else
  begin
  d:=2;
    while (d<=y) and (k=true) do
    begin

      if (x mod d=0) and (y mod d=0) then k:=false;
      inc(d);
    end;
  end;
  sim:=k;
end;
begin
  assign(f,'fractii.in');
  assign(g,'fractii.out');
  reset(f); rewrite(g);
  while not eof(f) do
      begin
        read(f,n);
        nr:=0;
        for i:=1 to n do
          begin
            for j:=1 to i do
              if sim(i,j) then
               begin
                 inc(nr);
               end;
          end;
        nr:=nr*2-1;
        writeln(g,nr);
       end;
  close(f);close(g);
end.