program bfracti;
var s,i,j,a,b,n,x,y,i1,k:longint;
     f1,f2:text;
     kb:boolean;

function prim(a,b:longint):boolean;
var pr:boolean;
begin
prim:=true;
for i1 := 2 to a do
   if (a mod i1=0) and (b mod i1=0) then
      begin
      prim:=false;
      exit;
      end;
end;



begin
assign(f1,'fractii.in'); reset(f1);
assign(f2,'fractii.out'); rewrite(f2);
read(f1,n);
s:=2*n-1;

for i:=2 to n do
  for j:=i+1 to n do
  begin
   if ((i mod 2=0) and (j mod 2=0)) then
   else
      begin
      {for i1 := 2 to i do
         if (i mod i1=0) and (j mod i1=0) then}
            if (prim(i,j)) then
             begin
              s:=s+2;
            end;
      end;
  end;
write(f2,s);
close(f1);
close(f2);
end.