Problem:
Counting Characters

Write a program which counts and reports the number of each alphabetical letter. Ignore the case of characters.

Input

A sentence in English is given in several lines.

Output

Prints the number of alphabetical letters in the following format:

a : The number of 'a'
b : The number of 'b'
c : The number of 'c'
.
.
z : The number of 'z'

Constraints

The number of characters in the sentence < 1200

Sample Input

This is a pen.

Sample Output

a : 1
b : 0
c : 0
d : 0
e : 1
f : 0
g : 0
h : 1
i : 2
j : 0
k : 0
l : 0
m : 0
n : 1
o : 0
p : 1
q : 0
r : 0
s : 2
t : 1
u : 0
v : 0
w : 0
x : 0
y : 0
z : 0

Solution in Ruby (judge verdict: Accepted)

sentences = $stdin.readlines

alphabets = {"a" => 0, "b" => 0, "c" => 0, "d" => 0, "e" => 0, "f" => 0,
             "g" => 0, "h" => 0, "i" => 0, "j" => 0, "k" => 0, "l" => 0,
             "m" => 0, "n" => 0, "o" => 0, "p" => 0, "q" => 0, "r" => 0,
             "s" => 0, "t" => 0, "u" => 0, "v" => 0, "w" => 0, "x" => 0,
             "y" => 0, "z" => 0}

sentences.each do |sentence|
   sentence.each_char do |char|
      if /[a-z]/i =~ char
         alphabets["#{char.downcase}"] += 1
      end
   end
end

alphabets.each do |key, val|
   puts "#{key} : #{val}"
end