图片发自简书App
size: 8*8 chess board
piece: one king, one queen,two rooks, two knights, two bishops and eight pawns.
from left to right:a,b,c,d,e,f,g,h.
from top to bottom:8,7,6,5,4,3,2,1
left side: Q-side
right side: K-side
a1~h1:white rook,white knight,white bishop,white queen,white king,white bishop,white knight, white rook
a2~h2:white pawns
