题解 | #字符串排序#

s = input()
a = ''
for i in s:
    if i.isalpha():
        a += i
aa = sorted(a,key=str.upper)
res = []
idx = 0
for i in range(len(s)):
    if not s[i].isalpha():
        res.append(s[i])
    else:
        res.append(aa[idx])
        idx += 1
print(''.join(res))