题解 | #字符串合并处理#

str1, str2 = input().split()

str3 = list(str1+str2)

str3[::2] = sorted(str3[::2])
str3[1::2] = sorted(str3[1::2])

res = []
for i in str3:
    if i in '0123456789abcdefABCDEF':
        tmp = bin(int(i,16))[2:].rjust(4,'0')[::-1]  # 按照16进制进解析成二进制
        r = hex(int(tmp,2))[2:].upper() # 按照二进制转换成16进制
        res.append(r)
    else:
        res.append(i)

for i in res:
    print(i,end='')