题解 | 牛牛的考试

T = int(input())

for _ in range(T):
    oa = input()
    ob = input()
    oc = input()
    od = input()

    s = [len(oa), len(ob), len(oc), len(od)]

    s_max = max(s)
    s_min = min(s)

    s_max_index = s.index(s_max)
    s_min_index = s.index(s_min)

    if s.count(s_min) == 1 and s.count(s_max) != 1:
        num = s_min_index
    elif s.count(s_max) == 1 and s.count(s_min) != 1:
        num = s_max_index
    else:
        num = 2

    print("ABCD"[num])