def get_first_letter(char):

char=char.encode('GBK')

if char<b"\xb0\xa1" or char>b"\xd7\xf9":

return ""

if char<b"\xb0\xc4":

return "a"

if char<b"\xb2\xc0":

return "b"

if char<b"\xb4\xed":

return "c"

if char<b"\xb6\xe9":

return "d"

if char<b"\xb7\xa1":

return "e"

if char<b"\xb8\xc0":

return "f"

if char<b"\xb9\xfd":

return "g"

if char<b"\xbb\xf6":

return "h"

if char<b"\xbf\xa5":

return "j"

if char<b"\xc0\xab":

return "k"

if char<b"\xc2\xe7":

return "l"

if char<b"\xc4\xc2":

return "m"

if char<b"\xc5\xb5":

return "n"

if char<b"\xc5\xbd":

return "o"

if char<b"\xc6\xd9":

return "p"

if char<b"\xc8\xba":

return "q"

if char<b"\xc8\xf5":

return "r"

if char<b"\xcb\xf9":

return "s"

if char<b"\xcd\xd9":

return "t"

if char<b"\xce\xf3":

return "w"

if char<b"\xd1\x88":

return "x"

if char<b"\xd4\xd0":

return "y"

if char<b"\xd7\xf9":

return "z"