a bằng 0 thì b bằng 56
..........1.................55
..........2.................54
.........3.................53
..........4.................52
..........5..................51.
..........6..................50
..........7..................49.
...........8..................48
...........9.................47.
...........10.................46.
...........11..................45.
...........12.................44
...........13.................43.
............14...............42
..........15..................41
...........16.................40
............17...............39
............18...............38.
............19...............37.
.............20...............36
.............21................35
.............22................34
.............23.................33
.............24..................32
.............25..................31
.............26...................30
.............27...................29
.............28...................28
VÀ NGƯỢC LẠI...
TICK CHO MÌNH NHÉ