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 C# (judge verdict: Time Limit Exceeded)

using System;
using System.Linq;

namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                int[] array = new int[26];
                string alpha = "abcdefghijklmnopqrstuvwxyz";

                while (true)
                {
                    string input = Console.ReadLine();

                    if (input == null || input.Length == 0)
                    {
                        break;
                    }

                    for (int i = 0; i < input.Length; i++)
                    {
                        if (char.IsLower(input[i]))
                        {
                            int num = input[i] - 'a';
                            array[num]++;
                        }
                        else if (char.IsUpper(input[i]))
                        {
                            int num = input[i] - 'A';
                            array[num]++;
                        }
                    }
                }

                for (int i = 0; i < array.Count(); i++)
                {
                    Console.WriteLine(alpha[i] + " : " + array[i]);
                }
            }
        }
    }
}