The UNICODEWIDTH function specifies the length of a display unit for
the Unicode data. The display unit displays the width of a character
when the character is displayed with fixed width font. Characters
between 0x3000 and 0x303F, 0x3400 and 0x4DFF, 0x4E00 and 0x9FFF, 0xF900
and 0xFAFF, inclusively, have the value of a display unit 2. Other
characters are display unit 1.