题解 | 牛牛的考试

T=int(input())
for i in range(T):
    AA=input()
    BB=input()
    CC=input()
    DD=input()
    y=['A','B','C','D']  
    LA=len(AA)
    LB=len(BB)
    LC=len(CC)
    LD=len(DD)
    L=[LA,LB,LC,LD]
    min_count=L.count(min(L))
    max_count=L.count(max(L))
    if min_count==1 and max_count!=1:#一短三长
        print(y[L.index(min(L))])
    elif max_count==1 and min_count!=1:
        print(y[L.index(max(L))])
    else:
        print('C')