procedure FileSort(var f: TFType);
var
    min:string;
    mini, i, head:integer;
    t, t2: TType;
begin
    reset(f);
    head := 0;
    while (head < FileSize(f)) do begin
        min := "";
        for i := FileSize(f) - 1 downto head do begin
            Seek(f, i);
            read(f, t);
            if (min = "") or (t.s < min) then begin
                min := t.s;
                mini := i;
            end;
            Seek(f, i + 1);
            write(f, t);
        end;
        Seek(f, mini);
        read(f, t);
        Seek(f, head);
        read(f, t2);
        write(f, t);
        Seek(f, mini);
        write(f, t2);
        inc(head);
    end;
    close(f);
end;