题解 | #表示数字#

s = input()

res = ''
flag = False # 开关
for c in s:
    if c.isdigit() and flag == False: # 数字子串开头    
        flag = not flag
        res += '*'
        res += c
    elif c.isdigit() and flag == True: # 数字子串过程        
        res += c
    elif not c.isdigit() and flag == True: # 数字子串结尾
        flag = not flag
        res += '*'
        res += c
    else:
        res += c
# 如果最后一位是数字，补全一个*
if s[-1].isdigit():
     res += '*'

print(res)