problema 1

def noAlpha(s):
# @param s: str
# @return str
  newString=""
  for i in range(0,len(s)):
    if not s[i].isalpha():
      newString=newString+s[i]
  return newString

def noAlphaWhile(s):
# @param s: str
# @return str
  newString=""
  i=0
  while i<len(s):
    if not s[i].isalpha():
      newString=newString+s[i]
    i=i+1
  return newString

def noNumbers(s):
# @param s: str
# @return str
  newString=""
  for i in range(0,len(s)):
    if not s[i].isdigit():
      newString=newString+s[i]
  return newString


def noNumbersWhile(s):
# @param s: str
# @return str
  newString=""
  i=0
  while i<len(s):
    if not s[i].isdigit():
      newString=newString+s[i]
    i=i+1
  return newString