program p1;
var i,j,nr,n:longint;
    f,g:text;

function cmmdc(x:longint;y:longint):integer;
var r:integer;
begin
     r:=x mod y;
     while r<>0 do
           begin
                x:=y;
                y:=r;
                r:=x mod y;
           end;
     cmmdc:=y;
end;

begin
     assign(f,'fractii.in');reset(f);
     assign(g,'fractii.out');rewrite(g);
     read(f,n);
     nr:=1;
     for i:=1 to n-1 do
         for j:=i+1 to n do
             if cmmdc(i,j)=1 then nr:=nr+2;
     writeln(g,nr);
     close(f);
     close(g);
end.