c = ?a
c = ?abc
c = ?\n
c = ?\s
c = ?\\
c = ?\u{41}
c = ?\C-a
c = ?\M-a
c = ?\M-\C-a
c = ?\C-\M-a
c = ?あ
c = ?/
c = ?\123
c = ?\xA1
c = ?\uAF09
c = ?\cx
c = ?\c\M-x
c = ?\c?
c = ?\C-?
c = ?\u{00AF09}
c = ?\u{0AF09}
c = ?\u{AF9}
c = ?\u{F9}
c = ?\u{F}