File list (Check if you may need any files):
Letter Recognition Data Set
...........................\optdigits-orig.tra
...........................\optdigits-orig.wdep
...........................\optdigits-orig.windep
...........................\optdigits.names
...........................\optdigits.tes
...........................\optdigits.tra
...........................\新建 文本文档 (2).txt
...........................\新建 文本文档.txt
letter-recognition
..................\letter-recognition.data
..................\letter-recognition.data.Z
..................\letter-recognition.names
..................\新建 文本文档.txt