"""File:     sort_string1.py
   Purpose:  Sort the characters in a string into increasing order

   Run:      python sort_string1.py

   Input:    A string consisting of lower-case letters
   Output:   The strings characters sorted in increasing order
"""
def how_many(let, s):
   """Count the number of times let occurs in s"""
   count = 0
   for l in s:
      if l == let:
         count = count+1
   return count

#----------------------------------------------------------------------
def sort_string(s):
   """Sort the characters in s into increasing order"""
   t = "" 
   for let in "abcdefghijklmnopqrstuvwxyz":
      count = how_many(let,s)
      if count > 0:
         t = t + count*let
   return t

#----------------------------------------------------------------------
word = raw_input("Enter a word\n   ")

sorted = sort_string(word)

print "After sorting the letters in", word, "we have", sorted