题解 | #字符串合并处理#

a = input().split()
a1 = a[0] + a[1]
奇数 = []
偶数 = []
for i in range(1, len(a1) + 1):
    if i == 1:
        奇数.append(a1[0])
    elif i % 2 == 0:
        偶数.append(a1[i - 1])
    else:
        奇数.append(a1[i - 1])
偶数.sort()
奇数.sort()
str1 = ""
for i in range(max(len(奇数), len(偶数))):
    if i + 1 > len(奇数):
        str1 += 偶数[i]
    elif i + 1 > len(偶数):
        str1 += 奇数[i]
    else:
        str1 = str1 + 奇数[i] + 偶数[i]
result = ""
for i in range(len(str1)):
    if str1[i] in [str(x) for x in range(10)]:
        a1 = str(bin(int(str1[i]))[2:].zfill(4))[::-1]
        result += format(int(a1, 2), "X")
    elif str1[i] in ["A", "B", "C", "D", "E", "F"]:
        a1 = int(str1[i], 16)
        a2 = str(bin(a1)[2:].zfill(4))[::-1]
        result += format(int(a2, 2), "X")
    elif str1[i] in ["a", "b", "c", "d", "e", "f"]:
        a1 = int(str1[i].upper(), 16)
        a2 = str(bin(a1)[2:].zfill(4))[::-1]
        result += format(int(a2, 2), "X")
    else:
        result += str1[i]
print(result)