2024-10-01

# n = int(input())
# data = []
# max = 0
# for i in range(n):
#
#     name, score = input().split()
#     name = str(name)
#     score = int(score)
#     data.append([name, score])
#
# for i in range(len(data)):
#
#     if data[max][1] < data[i][1]:
#         max = i
# data[max][1] = 0
#
# for i in range(len(data)):
#
#     if data[max][1] < data[i][1]:
#         max = i
# data[max][1] = 0
#
# for i in range(len(data)):
#
#     if data[max][1] < data[i][1]:
#         max = i
# print(data[max][0])

# data = []
# odd = []
# for i in range(7):
#     juwon = input()
#     juwon = int(juwon)
#     data.append(juwon)
#
# for i in range(7):
#     if data[i] % 2 != 0:
#         odd.append(data[i])
#
# if odd == []:
#     print('-1')
# else :
#     ni = sum(odd)
#     print(ni)
#     print(min(odd)

n = int(input())
data = []

for i in range(n * 2):
    v = list(map(int, input().split()))
    data.append(v)
    data[i].sort(reverse=True)
print(data)

for j in range(n):
    if data[j][0] == data[j + 1][0]:
        if data[j][1] > data[j + 1][1]:
            print('A')
        elif data[j][1] < data[j + 1][1]:
            print('B')
        else:

            print('D')

    elif data[j][0] > data[j + 1][0]:
        print('A')
    else :
        print('B')