var i,n,j,a,b,cn,r:longint;
    f,g:text;
begin
     assign(f,'fractii.in');
     assign(g,'fractii.out');
     reset(f);
     rewrite(g);
     readln(f,n);
     cn:=n;
     for i:=2 to n do
         for j:=1 to n do
             begin
                  if (i>=2) and (i<>j) then
                     begin
                          a:=i;
                          b:=j;
                          while a mod b<>0 do
                                begin
                                     r:=a mod b;
                                     a:=b;
                                     b:=r;
                                end;
                          if b=1 then inc(cn);
                     end;
             end;
     write(g,cn);
     close(f);
     close(g);
end.