题解 | #字符串合并处理#

str1,str2 = input().split()
str_merge = str1 + str2
str1_sort = ''
str2_sort = ''
str_result = ''
Odd_number = 0
Even_number = 0
result = ''
for i in range(len(str_merge)):
    if i%2 == 0:
        str1_sort += str_merge[i]
    else:
        str2_sort += str_merge[i]
for i in range(len(str_merge)):
    if i%2 == 0:
        str_result += sorted(str1_sort)[Odd_number]
        Odd_number += 1
    else:
        str_result += sorted(str2_sort)[Even_number]
        Even_number += 1
for i in str_result:
    if i.isalpha():
        if not ord(i.lower())>ord('f'):
            i = ord(i.lower())-ord('a')+10
            i = f'{int(i):04b}'[::-1]
            if int(i,2) < 10:
                result += str(int(i,2))
            else:
                result += chr(int(i,2)+ord('A')-10)
        else:
            result += i
    else:
        i = f'{int(i):04b}'[::-1]
        if int(i,2) < 10:
            result += str(int(i,2))
        else:
            result += chr(int(i,2)+ord('A')-10)
print(result)