³°ÅÁ ¡Ö¥é¥Ö¥¹¥È¡× º´Æ£ ½ßÌé¡¢Á¥ÄŠůʿ http://doga.jp/contest/con18/html/18_e21.htm ¤Ë¤Ä¤¤¤Æ¤Î´¶Áۤʤɤò½ñ¤¹þ¤à¥¹¥ì¥Ã¥É¤Ç¤¹¡£ [¤³¤Îµ»ö¤ËÊÖ¿®]