board the plane

# Arrange a boarding list for passengers on a plane, starting from the rear (higher row numbers)
# and boarding window seats (A and D) in front of aisle seats (B and C)

class Seat:
    def __init__(self, number, place):
        self.number = number
        self.place = place

    def __str__(self):
        return str(self.number) + self.place

# raw data
data = ["6C", "8A", "2B", "6D", "4C", "1B", "7C", "10B", "6A", "8C", "11C", "11A", "9B", "6B", "11D"]

seats = []

for e in data:
    seats.append(Seat(int(''.join([d for d in e if d.isdigit()])), ''.join([c for c in e if c.isalpha()])))

print(*seats)
seats.sort(key=lambda x: (x.number, x.place == 'A' or x.place == 'D'), reverse=True)
print(*seats)