题解 | #字符串排序#

while True:
    try:
        s = input()
        a = ""
        for i in s:
            if i.isalpha():
                a += i
        b = sorted(a, key=str.upper)  # 注意这个排序方法，upper后无()
        index = 0
        d = ""
        for i in s:
            if i.isalpha():
                d = d + b[index]
                index += 1
            else:
                d = d + i
        print(d)
    except:
        break