'C'.output
'1'.output
' '.output
'C'.output
'1'.output
' '.output
'C'.output
'2'.output
' '.output
'C'.output
'2'.output
' '.output
'1'.output
' '.output
#alt4# init
'1'.output
' '.output
#alt4# init
'D'.output
'2'.output
' '.output
'D'.output
'2'.output
' '.output