def parse(string):
if not string:
return ''
character, *arg = string
if character.isdigit():
return character + parse(arg)
return parse(arg)
t = parse(s)
t = ''
for char in s:
if char.isdigit():
t += char
def parse(string):
if not string:
return ''
character, *arg = string
if character.isdigit():
return character + parse(arg)
return parse(arg)
t = parse(s)