program bien_doi;
uses crt;
var n,i:integer;
{---Ham-nguyen-to---}
function ktnt(k:integer):boolean;
var e:integer;
begin
ktnt:=false;
if k<2 then exit;
for e:=2 to trunc(sqrt(k)) do
if k mod e=0 then exit;
ktnt:=true;
end;
{---Chuong-trinh-chinh---}
BEGIN
clrscr;
write('Nhap N: '); readln(n);
for i:=2 to n div 2 do
if ktnt(i) and ktnt(n-i) then writeln(i,' ',n-i);
readln;
end.