题解 | #字符串合并处理#

l_input = input().split(" ")
s = l_input[0] + l_input[1]
l = list(s)


# 十六进制倒过来
def fhex(val):
    val =bin(val)[:1:-1]
    while len(val)<4:
        val+="0"
    return hex(int(val,2))[2].upper()


# 奇偶
ji = []
ou = []
for i in range(len(l)):
    if i % 2:
        ji.append(l[i])
    else:
        ou.append(l[i])
ji.sort()
ou.sort()
i_ji = 0
i_ou = 0
new_l = []
for i in range(len(l)):
    if i % 2:
        new_l.append(ji[i_ji])
        i_ji += 1
    else:
        new_l.append(ou[i_ou])
        i_ou += 1
l = new_l
new_l = []
for val in l:
    if 'a' <= val <= 'f':
        val = ord(val) - ord('a') + 10
        new_l.append(fhex(val))
    elif 'A' <= val <= 'F':
        val = ord(val) - ord('A') + 10
        new_l.append(fhex(val))
    elif '0' <= val <= '9':
        val = int(val)
        new_l.append(fhex(val))
    else:
        new_l.append(val)
print("".join(new_l))