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)

arr = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"]
a_count = Array.new(26)
s_count = 0
count = 0
26.times do |i|
  a_count[i] = 0
end
s = []
while s[s_count] = gets
  s[s_count] = s[s_count].downcase.split("")
  s_count += 1
end
s.flatten!
arr.each do |item|
  s.size.times do |i|
    if s[i] == item
      a_count[count] += 1
    end
  end
  puts "#{item} : #{a_count[count]}"
  count += 1
end